Hey Everyone,

I've been a lurker on here for a while now, thought I'd finally pop in and get involved a bit. This is a very nice Dmax site!

I've got an '06 G3500 Savana, stripped version, 135" cargo. Bought it early this year with ~50K on it, seems to run great. I sold my '86 Burb (with 1 tons) and this replaced it for a toy. It'll be my camper van when I'm done. I used it for towing jet ski's to the lake, as well as picking up metal at the supplier. It also hauled around some 3 wheeler's for a while this summer. All around it's a decent van (few complaints about the body, but overall it's decent).

In mid-Oct, in my driveway, I put it up on jack stands and started cutting it up. My plasma cutter did a great job at hacking off the front suspension, which is being replaced with a solid front axle. It's got 10" travel King coilovers suspending it up front, and custom radius arms locating it. The ride height will be 6" higher than stock, initially, hopefully to settle to 5" with some more weight (winch, bumpers, etc). The rear is spring by custom Alcan spring pack and Bilstein 7100's (shocks will be here Wednesday, springs are in). I removed the ABS and am in the process of replumbing the brakes with AN fittings/lines. Running the fronts down the radius arms.

I hope to have it back on the road by Christmas. Have to see how it goes, gonna try to sling the axle back under it this weekend. It'll be wearing 315/70R17's on H2 wheels to start. I could fit 37's, but I think the 35's are big enough for now. After this axle is done, I'll be moving the fuel tank to the spare tire location, and clearing out room for a Ford NP205 Divorced T-case. This should bring it up to 4WD...then on the the bumpers and interior.

Well, that's about it for now. I appreciate any help and feedback in the project. I'm looking at using EFI Live for changing gearing/tire size...and this site seems like a great place for support of that tuner.

Good evening!
Joshua

Welcome aboard! Sounds like an interesting project. Any pics?

Welcome aboard! Sounds like an interesting project. Any pics?

Thanks for the welcome. I do have some pics (mock-up and fitment type right now), but haven't posted them online yet. I'm sort of waiting until it's all together in the next few weeks. I only have one mock-up tire I borrowed from a friend. Hoping to get my set of tires around Christmas time, pending a driving vehicle again. I plan to post up some pics then.

I have a list of parts I was hoping to order from you guys pretty soon (EGR block off, PCV reroute, exhaust, etc). Real quick...do the truck exhausts fit the vans as well? Looking for a 4" straight through + a downpipe ('direct' pipe seems like a silly name IMO). Thanks again!

The exhaust kits do fit, you'll just need to fine tune it and move the hangers around a bit. Nothing a good muffler shop (or yourself) couldn't do. The Downpipe is a direct bolt on and super easy with the dog house out of the way. Give us a shout when you're ready, we're running a good sale on everything you listed there.

Chad

The exhaust kits do fit, you'll just need to fine tune it and move the hangers around a bit. Nothing a good muffler shop (or yourself) couldn't do. The Downpipe is a direct bolt on and super easy with the dog house out of the way. Give us a shout when you're ready, we're running a good sale on everything you listed there.

Chad

Thanks Chad. I will definitely be giving you a shout when the time comes. Gotta get the rest back together first, and my wallet has taken a beating lately trying to get the remainder of parts in.

I understand the wallet beating. Been building a race motor the last few months, it ain't cheap... Let me know when you're ready.

Chad

Chad's a great guy to deal with and you won't be disappointed when you add more power. These vans wake up nicely with a few goodies. Good luck with your build, it sounds pretty sweet.

Chad's a great guy to deal with and you won't be disappointed when you add more power. These vans wake up nicely with a few goodies. Good luck with your build, it sounds pretty sweet.

:beerchug:

Chad's a great guy to deal with and you won't be disappointed when you add more power. These vans wake up nicely with a few goodies. Good luck with your build, it sounds pretty sweet.

Have a suggestion on the goodies...maybe by priority as you see it?

Tranny first? Exhaust? I'm thinking EGR first...then what?

Some mock-up and in-process pics (best I have for now, I'm a worker, not a photographer). Axle should be under it, all painted, this weekend for the last time.

Welding up the front axle as driver's side drop
http://i1008.photobucket.com/albums/af205/independence330/IMG_3964.jpg

Coilover's in for the first time
http://i1008.photobucket.com/albums/af205/independence330/COmockup.jpg

315/70R17 BFG AT on H2's (mock-up wheel) front driver corner only. Stock rear springs.
http://i1008.photobucket.com/albums/af205/independence330/WheelMockup.jpg

Ride height as-is today (6" compression, 4" rebound travel).
http://i1008.photobucket.com/albums/af205/independence330/IMG_4670.jpg

Hell yes! I want mine to be like that!

Look, I don't mean to rain on your parade, but there is a fatal flaw to your front suspension design. You should not be using a radius rod style control arms (2 link) with a solid front axle. Heres why: When one wheel hits a bump and travels upward, the ball joint axis moves in an arc in the radius of the control arm. The caster angle of the wheel hitting the bump will change as it moves upward, but the opposite wheel wants to remain the same, since it is not moving. One of three things will happen: 1. The axle will twist. 2. One of the control arms will bend. 3. The opposite wheel will move upward also. Because everything you fabricated looks pretty stout, #3 is the most likely, and the ride will be terrible; every movement of the left wheel will be duplicated by the right. Besides being uncomfortable, this will be unsafe at highway speed. This is why Ford and Dodge use a 4-link setup. Old hotrods with split wishbones could get away with this (for awhile) because the i-beam axle would twist. Same with the old ford twin I-beam. Don't kill the messenger, I just don't want you to get hurt.

Check out these photos for a correct sfa conversion: http://www.dieselplace.com/forum/showthread.php?t=399847

Look, I don't mean to rain on your parade, but there is a fatal flaw to your front suspension design. You should not be using a radius rod style control arms (2 link) with a solid front axle. Heres why: When one wheel hits a bump and travels upward, the ball joint axis moves in an arc in the radius of the control arm. The caster angle of the wheel hitting the bump will change as it moves upward, but the opposite wheel wants to remain the same, since it is not moving. One of three things will happen: 1. The axle will twist. 2. One of the control arms will bend. 3. The opposite wheel will move upward also. Because everything you fabricated looks pretty stout, #3 is the most likely, and the ride will be terrible; every movement of the left wheel will be duplicated by the right. Besides being uncomfortable, this will be unsafe at highway speed. This is why Ford and Dodge use a 4-link setup. Old hotrods with split wishbones could get away with this (for awhile) because the i-beam axle would twist. Same with the old ford twin I-beam. Don't kill the messenger, I just don't want you to get hurt.

I would say you don't understand radius arm suspension. None of the things you mentioned will happen.
Ford has used radius arm suspensions on the old 77-79 F 150's and old Bronco's with great success. it's a simple and great working setup.
They like it so much they designed the new, 05 and up F250's through F550's with a radius arm system.
The downside to them is castor angle changes as the suspension cycles, but i doubt it will be an issue on this van.

cool pics cant wait to see the rear end lifted

Look, I don't mean to rain on your parade, but there is a fatal flaw to your front suspension design. You should not be using a radius rod style control arms (2 link) with a solid front axle. Heres why: When one wheel hits a bump and travels upward, the ball joint axis moves in an arc in the radius of the control arm. The caster angle of the wheel hitting the bump will change as it moves upward, but the opposite wheel wants to remain the same, since it is not moving. One of three things will happen: 1. The axle will twist. 2. One of the control arms will bend. 3. The opposite wheel will move upward also. Because everything you fabricated looks pretty stout, #3 is the most likely, and the ride will be terrible; every movement of the left wheel will be duplicated by the right. Besides being uncomfortable, this will be unsafe at highway speed. This is why Ford and Dodge use a 4-link setup. Old hotrods with split wishbones could get away with this (for awhile) because the i-beam axle would twist. Same with the old ford twin I-beam. Don't kill the messenger, I just don't want you to get hurt.

As JOey D said, I think you're missing some crucial details that could have generated good questions. I'll list some important parameters for you while I describe what I'm doing.
* How long are the radius arms? The shorter they are, the more the axle will want to twist on stuff/rebound. These are in the 38" long range from axle center line to rear bushing.
* What bushing is being used on the radius arms at the frame end? A ballistic joint (think Johnny joint). It's not a rubber bushing, so the radius arm is free to rotate relative the frame in all directions (where some bind comes from on a radius arm set-up).
* How are the radius arms connected to the axle? Big rubber bushings top and bottom. They will compress as the axle articulates. Should have taken a pic of it flexing a few weeks ago with the floor jack under one side...
* What is the separation of the radius arms 1. at the axle and 2. at the frame. The are parallel, and ~36" wide at each.
* What is the travel of the CO's, and what is their separation? 10" and ~44" IIRC.

Yous are correct, everything is stout and the axle will try to twist. There are rubber bushings to accommodate this though. The radius arms are NOT rigidly mounted to the axle through heims or otherwise. The caster will change as suspension cycles. The desert guys seems to be okay with that. Same with Carli and Thuren on the big Dodge trucks with their radius arms. In fact, Ford Super Duties have a VERY similar suspension design in '05 to current trucks. Seems to be fine for them too. Jeep guys often replace their 4 links with radius arms (think "long arm" kits). It's a proven design that should work well. I'd love to have a 4-link + panhard, but given my desire to keep lift to a minimum, I couldn't clear engine mounts mostly for the upper links. Maybe I'll look into it more in the future, but for now this should work well.

Please note, I didn't read your comments as flaming or negative, and appreciate your concern and input. I hope this response will hep to enlighten the solution I'm using and make sense. Thanks for the feedback!

cool pics cant wait to see the rear end lifted

Thanks. It looks MUCH better with the rear lifted AND the big tires. Can't wait to get the tires on (have to select and buy some first though). I'll post pics when I get that far.

I would say you don't understand radius arm suspension. None of the things you mentioned will happen.
Ford has used radius arm suspensions on the old 77-79 F 150's and old Bronco's with great success. it's a simple and great working setup.
They like it so much they designed the new, 05 and up F250's through F550's with a radius arm system.
The downside to them is castor angle changes as the suspension cycles, but i doubt it will be an issue on this van.

Caster angle is the downside, although I'm not sure it matters much in most vehicles/applications. A lot of the desert guys use radius arms up front. Several companies are offering radius arm set-ups for the Dodge HD's now (Carli Suspension, Don Thuren, and even Kore had some prototypes at least). A plus is that the pinion angle is well controlled through travel, helping driveshafts survive. Obviously, the longer the radius arms and/or the shorter the travel, the less the caster angle changes. Technically, unless it's an equal length/parallel 4-link set-up, caster also changes on 4-links, just less overall through the travel.

I do want to state for the record, I don't think its as simple as a leaf set-up in terms of fabrication, and I believe that a leaf set-up is simply a spring and radius arm built into one (reverse radius arm/trailing arm). I have NO desire to put leaves on this vehicle up front though.

I would say you don't understand radius arm suspension. None of the things you mentioned will happen.
Ford has used radius arm suspensions on the old 77-79 F 150's and old Bronco's with great success. it's a simple and great working setup.
They like it so much they designed the new, 05 and up F250's through F550's with a radius arm system.
The downside to them is castor angle changes as the suspension cycles, but i doubt it will be an issue on this van.

I would say YOU don't understand physics and mechanics.

As JOey D said, I think you're missing some crucial details that could have generated good questions. I'll list some important parameters for you while I describe what I'm doing.
* How long are the radius arms? The shorter they are, the more the axle will want to twist on stuff/rebound. These are in the 38" long range from axle center line to rear bushing.
* What bushing is being used on the radius arms at the frame end? A ballistic joint (think Johnny joint). It's not a rubber bushing, so the radius arm is free to rotate relative the frame in all directions (where some bind comes from on a radius arm set-up).
* How are the radius arms connected to the axle? Big rubber bushings top and bottom. They will compress as the axle articulates. Should have taken a pic of it flexing a few weeks ago with the floor jack under one side...
* What is the separation of the radius arms 1. at the axle and 2. at the frame. The are parallel, and ~36" wide at each.
* What is the travel of the CO's, and what is their separation? 10" and ~44" IIRC.

Yous are correct, everything is stout and the axle will try to twist. There are rubber bushings to accommodate this though. The radius arms are NOT rigidly mounted to the axle through heims or otherwise. The caster will change as suspension cycles. The desert guys seems to be okay with that. Same with Carli and Thuren on the big Dodge trucks with their radius arms. In fact, Ford Super Duties have a VERY similar suspension design in '05 to current trucks. Seems to be fine for them too. Jeep guys often replace their 4 links with radius arms (think "long arm" kits). It's a proven design that should work well. I'd love to have a 4-link + panhard, but given my desire to keep lift to a minimum, I couldn't clear engine mounts mostly for the upper links. Maybe I'll look into it more in the future, but for now this should work well.

Please note, I didn't read your comments as flaming or negative, and appreciate your concern and input. I hope this response will hep to enlighten the solution I'm using and make sense. Thanks for the feedback!

The connection of the radius arms to the axle was the one connection I could not see, and you are correct in that a flexible connection will help mitigate the torsional forces, hopefully enough. Have you also given any thought to the change in pinion angle and the effect on the universal joints?
Thank you for taking my comments in the spirit in which they were intended. Good luch with your project.

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The connection of the radius arms to the axle was the one connection I could not see, and you are correct in that a flexible connection will help mitigate the torsional forces, hopefully enough. Have you also given any thought to the change in pinion angle and the effect on the universal joints?
Thank you for taking my comments in the spirit in which they were intended. Good luch with your project.

The pics I posted certainly don't show many details, rather the idea was to give a general direction of where the project is going. Something to remember: these are only 10" travel CO's, not super long for rock crawling. With 10" of CO travel, at full articulation that's about 14" total travel one side to the other. I don't have my notes in front of me right now, but I seem to remember that the bushings only have to deflect ~1/4" each, which isn't much given the overall bushing size/rubber thickness. I'm not using Super Duty bushings at the axle BTW. The bushings are stock Dodge Ram pieces, 5/8" bolts, top and bottom. I believe the stock Dodge arrangement is a big bushing on the bottom and a small one on top. Mine are all big versions. Coincidentally, these bushings are the same as the Jeep guys use and have great success with for radius arms (they have small bolt sizes though).

I say this because the Jeep guys use shorter radius arms typically, at a higher angle (mine are almost horizontal at ride height), and they flex more than this ever will. If I had my choice, I'd have done a 4-link, but I just couldn't bring myself to jack this up that much. I use it for towing and camping, and didn't need 9"+ in added suspension height! The Radius arms were a compromise, one that I think will work fine given the breathe of others that use them. Heck, even Toyota has radius arms in their Land Cruiser's, and they worked well too...

As for pinion angle, it'll follow the radius arms during regular compression/rebound. I'm using a divorce mounted NP205 (when I find one), and will be mounting it such that both front and rear shafts are the same length. I also plan on using 1410 U-joints throughout. This shouldn't be any issue at all. The length of the driveshafts, combined with the lower overall ride height will make the U-joints happy. I'm not planning on even running a CV at the T-case end. Oh, and I am planning on clocking the T-case up a bit for better center clearance and a flat skid plate.

Again, I appreciate the input and any constructive criticism.

I would say YOU don't understand physics and mechanics.

I do understand physics and mechanics. If you spent any time at all building and working on suspension systems you would understand the design in question and have not posted what you did.

OK Joey, I will go over this one more time, pay attention: your first post said: "None of the things you mentioned will happen" In fact, one or a combination of the things will most certainly happen IF not addressed in the design. "Jlane" was happy to explain how he was dealing with this real problem. I am not familiar with Ford front suspensions, and make no apology for that, but I am familiar with the science involved.

OK Joey, I will go over this one more time, pay attention: your first post said: "None of the things you mentioned will happen" In fact, one or a combination of the things will most certainly happen IF not addressed in the design. "Jlane" was happy to explain how he was dealing with this real problem. I am not familiar with Ford front suspensions, and make no apology for that, but I am familiar with the science involved.

Have you ever looked at a radius arm design in person?

The Super60 DANA is such a right on axle design in those Fords with the different designed linked needs wanted in GM SAS conversions makes looking for that old hi pinion Dana from the 70s' obsolete. Now a safe coilover design is on the horizon for a kit even with the amount of guys wanting to do a changeover starting to take notice to get rid of the IFS on a Dmax truck. That Super60 came from 05 until present right??? Just tried to keep it correct for topic clarity.

Yes the super 60 is in the 05 and up Fords. The only downsides to the axle is the metric lug pattern, unit bearings and abs.
The AAM out of the 03 and up Dodge trucks is a much better option. It uses the same bolt pattern, the abs plugs right in and there are kits to convert it to old style wheels bearings and lock out hubs.
You can make the abs work on the older axles and you can buy a caliper bracket to keep your GM HD brake setup, rotors and calipers will still work.
The options are out there to make it more appealing vs an IFS lift.

Yes the super 60 is in the 05 and up Fords. The only downsides to the axle is the metric lug pattern, unit bearings and abs.
The AAM out of the 03 and up Dodge trucks is a much better option. It uses the same bolt pattern, the abs plugs right in and there are kits to convert it to old style wheels bearings and lock out hubs.
You can make the abs work on the older axles and you can buy a caliper bracket to keep your GM HD brake setup, rotors and calipers will still work.
The options are out there to make it more appealing vs an IFS lift.

The other downside to both of these axles, IMO, is steering arm options. I'm not a fan of T or Y style steering, and feel personally that the draglink should go to the knuckle directly. The tierod should be from knuckle to knuckle only. I know the factory has done different variations, but this is my opinion. So, from that perspective, the king pin version's are nice since I can easily bolt a steering arm to the knuckle. There are downside however, namely the king pin tops require a LOT of room to clear coilovers (when mounted low on the axle tube), and the brakes aren't as good. I'm considering trying a brake upgrade in the future using the stock van caliper and slip on rotor. From the initial looks, it might work. Problem might be caliper to knuckle clearance issues (actually caliper/brake pad bracket, not the caliper itself).

I looked into using a Dodge HD front end on this, and the cost was pretty high when you add in the cost of a unit bearing eliminator and upgraded (Carli) ball joints. Might be better to have a custom axle built by the time all that is included. What's the state of lockers for a Ford SD Super 60? ARB available for that? Also, the Super 60's have massive axle tubes, and the radius arm brackets are huge, taking away oil pan clearance and requiring taller lifts. Finally, I don't think the stock coil mounts are beneficial to using CO's and keeping everything low. This might be fine for some people, but my goal was to keep the van as low as possible with good compression travel. I'm happy with 4-5" lift over stock and 35's. It looks right, IMO, and is still very usable for my purposes. The Super 60 would have required 7"+ of lift plus tires.

Anyway, there's more than one way to skin this cat. Oh, I meant to say, I think the trucks have more frame rail clearance over an axle than the vans. And obviously they have more room under the fender wells as well for CO's. The above info is in regard to my project, the van chassis/body.

I vote for a giant cargo roof rack with an off-road LED light bar on top.

that van's gonna look BAD ASS!!!

I vote for a giant cargo roof rack with an off-road LED light bar on top.

that van's gonna look BAD ASS!!!

Funny you should mention that. A buddy stopped by last night and we discussed cargo racks and perimeter lighting. I was telling him that I want electronically controlled lights up front so I can steer them side to side with a joystick (or buttons I guess). Just a simple little motor/linear drive sort of thing. Sadly, the rack will be a while in the making, so many other things to do first...definitely need some bumpers before a rack.

Thanks for the compliments! I think it looks pretty cool myself. I like the body styling of the Chevy vans...

Guess I should have posted up some progress. It's sitting on it's own wheels again, everything buttoned down. The steering is all hooked up and mostly bleed (ran out of steering fluid). The engines running, wiring rerouted were needed. Reservoirs are mounted, rear shocks are close to being mounted (had to make upper mount adapters for the 7100's into the stock shocks mounts). Last major item is brake plumbing. Heading to the store today to get some flex lines made. It's really close to first drive...

I'll post up some more pics when I get a chance.

Few more pics from this weekend. Axle install mostly. I think the springs I have (350 #/in X 22" long) are too stiff to get full articulation up front with the current vehicle weight. It also sits an 1 - 1.5" too high from what I wanted. I'll give the springs some time to settle, and figure out if I want shorter, softer or all the above springs (thinking maybe 300 X 20").

Last night the front brake calipers went on, along with some custom brake lines. I also got the rear shock reservoir hoses shortened and reassembled. I'm almost ready for a test drive...almost...

Pics of axle were at full compression (no shocks installed), to show clearances. Shots with coilovers installed is vehicle at current ride height.

http://i1008.photobucket.com/albums/af205/independence330/IMG_4696.jpg

http://i1008.photobucket.com/albums/af205/independence330/IMG_4733.jpg

http://i1008.photobucket.com/albums/af205/independence330/IMG_4725.jpg

http://i1008.photobucket.com/albums/af205/independence330/IMG_4709.jpg

http://i1008.photobucket.com/albums/af205/independence330/IMG_4701.jpg

http://i1008.photobucket.com/albums/af205/independence330/IMG_4697.jpg

http://i1008.photobucket.com/albums/af205/independence330/IMG_4707.jpg

Thats sick, subscribing

Figured I'd comment on articulation of the front axle given the earlier discussion. I put a jack under one of the radius arms (vehicle started on all 4 wheels) and started jacking. I jacked until a wheel (front or rear) came off the ground (or the jack ran out of travel, which didn't happen this trial). Here's the summary of what I saw. Please realize this was not a perfect test since my driveway is quite sloped, so getting robust numbers is difficult.

After jacking a bit under the drivers side radius arm bushings at the axle, I noticed that the passenger front tire lifted off the ground first. The rear springs did not flex as much as the stock ones, that was clear. My passenger side CO appeared to be fully extended, and the drivers side had ~3" of shaft showing. The tire had ~13" of gap to the concrete, and if I had to estimate what it would have been on a flat surface, I'd guess it would have been ~16" from bottom of tire to ground (compensating for the sloped driveway, the rear passenger tire is several inches higher than the drivers rear tire). Of course the tire also wasn't squished like it is at ride height, so overall wheel travel would have been maybe 17-18" on level ground if the tires were being compressed.

Is this good? Not as good as it was with the stock rear leafs. I think it makes sense though...these are designed to have another 800# on them (interior, rear bumper, spare tire, T-case, skid plate, relocated fuel tank, etc). So, they just can't flex as much as they are designed too, just too light right now.

Up front it's clear that there is not enough weight in this configuration to fully compress the spring, so it started lifting the complete front end teetering on the jack, balanced by the rear wheels. This again makes sense. The weight up front is only enough to compress the springs to ~7-8". I don't know exactly how much the front weighs without the stock suspension, wheels, etc, but I believe it was in the 3200# mark over the front axle in stock configuration without a driver. Subtract the A-arms, spindles, wheels, brakes, springs, sway bar and various brackets, and add back the frame brackets I put on, and the net is that the weight up front trying to compress the spring is far less than 3200#. So, at 350#/in springs, if it compressed the springs 7" (springs have NO preload when shocks are fully extended, but they aren't loose either), that's 2450#. The suspension bushings are adding articulation resistance too, but how much? No idea. Anyway, it's all well within the ball park and does indeed articulate. I could have pulled a bolt from one of the radius arm bushings to remove the effect of the twisting (wristed radius arm), but it's all buttoned down and it doesn't matter much since I won't be driving that way.

Ultimately I think I might need some front lighter springs. I'd also go shorter to lower the overall ride height and have flexibility there. Maybe 300# X 20" long. With a front bumper, front winch, recovery gear stored up front, T-case, etc...it should flex better given more weight. So, the bushings are working okay it would seem from the radius arms to the axle, and the radius arms are doing okay too. The flex joint at the back of the radius arm really works great allowing the arms to rotate side to side and not bind.

Again, not scientific, just observations gathered through curiosity...

EDIT: It all flexes MUCHO better than the stock van did. Sometimes I'd get stuck pulling one wheel over the curb to get into my driveway. It'd also hit the crossmember on the curb. Don't expect any more of those issues...haha!

Neat project

You are doing a really nice job...keep up the good work...

Loods great with them hummer front tires.

Thats sick, subscribing

Neat project

You are doing a really nice job...keep up the good work...

Loods great with them hummer front tires.

Thanks everyone!

I'm really looking forward to getting it back on the road. It'll be 2WD for the time being, but driving again would be a huge accomplishment. Given the weather right now, I think I lucked out this fall and am poised to finish just in time.

T-case is ordered, be here in about a month. In the mean time, I hope to move the fuel tank and get the fuel system worked out...planning on a header tank in place of the original, and a big tank where the spare currently is. Use a Carter diesel pump to transfer from the large tank to the header in a continuous feed/bleed to keep it topped off. The stock lift pump/filters will then feed off the header tank. Still working out the return and reading up on the fuel cooler.

Making great progress.
What are you doing for bump stops? Air bumps, hydro, rubber?
I did mention it already but there is a guy in Utah who makes caliper brackets so you can run a dual piston caliper and slip on rotor of the newer HD trucks. Much better setup than the old GM single piston or the old ford dual piston with the thin rotor

Making great progress.
What are you doing for bump stops? Air bumps, hydro, rubber?
I did mention it already but there is a guy in Utah who makes caliper brackets so you can run a dual piston caliper and slip on rotor of the newer HD trucks. Much better setup than the old GM single piston or the old ford dual piston with the thin rotor

I haven't done anything yet for bump stops. I have some ideas for putting in rubber versions, but haven't gotten that far. I have a feeling I'll be swapping front springs for lighter and/or shorter versions. At that time I'll put bumpstops in. Right now, if the shock bottoms, there is still clearance to the oil pan.

If you mentioned a brake upgrade, I must have missed it. Do you have any contact info? I'd love to find out more about this. Thanks!

Merry Christmas everyone! Have a few minutes...here's an update.

Got the brake plumbing completed Thursday evening. Started bleeding them (homemade powerbleeder works GREAT!), found a leak, got that fixed up (wasn't tightened, opps), finished bleedding them and the brakes felt good. Heck, it's 10:30, why not see if I can move and stop the thing. Started moving it from the driveway, and decided that it was going ok...haha...let's take it down the street. I still did not have rear shocks on it, and the pinion needed rotating down 8 degrees. Cruised around the neighborhood and everything was great. Stops VERY well, much better than expected. I have the rear brakes turned all the way down on the prop valve, and it still stops great. In fact, the pedal is much better than the stock brake system (firmer and more positive), and it stops better than stock. Turn radius is very good. I'd estimate that it's ~3-5 feet larger than the stock van based on being able to turn around at the end of the cul-d-sac in one big turn. It's very acceptible!

So, put decided to hed up and get some fuel. Two problems arised...a clunk in the back and a slight vibration in the driveshaft (expected). It also rides pretty stiff! Drove it ~30 minutes then put it away. Not steering damper on there yet, NO issues though in steering. No wobbles, nice and positive and stable. A success! Oh, I'm using the stock tires right now...waiting for a money tree to show up to buy some.

Yesterday morning I got out there early and cut the rear axle perches off and rotated the axle to get my angles corrected. I also cut the stock shock brackets off and mounted the Bilstein 7100's in the rear. By that point I had to pick up my son, so I put it away. Well, he wanted to go for a test drive, so we went out late in the afternoon and got it up to higher speeds (75). No drama, seemed to do well. Still a SLIGHT driveshaft vib though. Not sure why. I still have a loud clunk in the rear too. It can be very loud. Anyway, took it down some dirt roads that I'm familiar with and it rides MUCH better than the last time I took it down there. Stock compared to this was NIGHT AND DAY! The front ends works awesome.

We cruised around for about an hour or so and finished by taking some big hills (sand mixed with hardpack and baby head volcano droppings). We went slow, we went fast, up this side hill, down that one, etc. That clunking in the back was the only real problem. I checked the rear shock O-rings and they're only compressing 2" MAX from ride height, no more. The fronts are traveling well. We came home after hitting some big mud holes at speed and having a blast.

After getting home I thought about the rear clunk for a while and figured out what it is...The rear shackles/spring end is hitting the body in the back. The swing of the shackle is such that it hits the body upon compression. Looks like I'll be making new shackle hangers and probably longer shackles while I'm at it. Bummer! That should solve that issue though, and I expect it to ride great.

I would like to lower the front end with shorter shocks, and maybe go with lighter springs + add a sway bar. The sway isn't bad at all, but it could use a bar up front.

Overall the thing runs and drives great. That steering damper will be a nice addition, but without it it still drives very well. Bigger tires should also help out a lot. The stockers at 60 psi are pretty stiff. Planning on using Nitto Terra Grapplers in 305/70R17. Load E, nice heavy load rating, and about the right size. All the 35's seem to be Load D...concerned about sidewall stiffness. The nittos at a reasonable pressure should help with overall stiffness I'd think. Anyway, seems to be working well with minimal bugs to work out.

Few last observations:
1. It doesn't feel too bad driving it sitting over the front so much. Doesn't feel too high and the ride is good. Those King's seem to work well up there.

2. Got a few funny looks while sitting in traffic from some Jeep guys. They were lifted and didn't really understand why my van was so much taller.

3. Passed a Ferd Exploder and the roofline was about at the bottom of the door window. You certainly sit tall in that thing! Wow!

Does anybody know what happened to this guy ? I would like to hear an update on how this project has progressed.

Does anybody know what happened to this guy ? I would like to hear an update on how this project has progressed.

Wow, hadn't realized it's already been a year since my last update. Thanks for the reminder. Well, here's a quick update:

1. Been driving it around with the bigger tires and it drives great. Put new front springs on to get the ride height lowered a bit. Installed a Bilstein 7100 steering stabilizer (high mount). Never had any issues with death wobble or otherwise with or without the steering stabilizer.

2. Had it aligned and the shop told me the axle was straighter (as was the alignment) than most factory trucks. Not bad for doing it in the garage/driveway with tape measures and eye balls (and a few other measuring tools).

3. Divorced NP205 is in, connected with HAD front and rear driveshafts. Shifter sits right next to the front seat base, out of the way. I really need to figure out what NP205 switch I need so I can have a shift indicator. Oh...the shifter goes up/down versus front back, more like a parking brake handle to keep it low and unobtrusive. Works well.

4. 4" straight through exhaust custom built coming off a Diamond eye downpipe. Sounds good. It clears the rear leaf spring and the custom rear fuel tank (~42 gallons, replaced spare tire). Replumbed the fuel system, relocated the filters and lift pump the the frame rail.

5. Built a custom rear bumper, sprayed with Al's bed liner. Still have not finished the spare tire mount though.

6. Have EFI Live with speedo correction, some deletes, and a very mild tune from Nick @ duramax tuner. Tried to correct the fuel gauge readout to be more accurate, but haven't put much effort into it to be honest.

7. Front axle got regeared to 3.73 to match the rear, along with an ARB. I have a complete onboard air system as well waiting to be installed.

Overall the van runs and drives well. It flex's very well for what it is. It's very capable off road, and has done a good job in the sand, in the mud, and playing in the snow. It hauls firewood and the jet ski's well. Oh, it also doubles as a tent well. I still have a long list of things to do, but have been reconsidering the final goal of the project (originally it was supposed to be a GM sportsmobile like vehicle). Not sure what interior it needs/will get still.

To do:
A. Add at least 2 seats in the rear.
B. Find a rear locker/LSD/ARB for the D70S.
C. Front bumper and winch
D. Finish spare mount on rear bumper.
E. Install onboard air system and air horn ;)
F. Backup camera and new stereo system.
G. Finish interior.
H. Tint windows and make removable binds for complete no-see-through.

Some pics (need to take some of finished 4WD T-case/driveline/fuel tank when it's cleaned). It's covered in mud from cutting firewood last week.

http://i1008.photobucket.com/albums/af205/independence330/Van/P1000569.jpg

http://i1008.photobucket.com/albums/af205/independence330/Van/IMG_5150.jpg

Exhaust and front fuel tank crossmember:
http://i1008.photobucket.com/albums/af205/independence330/Van/IMG_5148.jpg

Rear bumper:
http://i1008.photobucket.com/albums/af205/independence330/Van/IMG_5143.jpg

Bumper/exhaust outlet:
http://i1008.photobucket.com/albums/af205/independence330/Van/IMG_5140.jpg

New treads:
http://i1008.photobucket.com/albums/af205/independence330/Van/IMG_5136.jpg

Why more isn't done:
http://i1008.photobucket.com/albums/af205/independence330/Van/P1000267.jpg

Looking good.

I like! I like ALOT!

Sweeeet! Love that rear bumper. Is your fuel tank behind the rear axle?

Looking good.

I like! I like ALOT!

Sweeeet! Love that rear bumper. Is your fuel tank behind the rear axle?

Thanks everyone. Yes, the fuel tank is behind the rear axle, and fills the space up to the bumper (rubber mounted to the bumper itself). I'll have to get some pics. It's made from 3/16" and 1/8" aluminum, and uses the stock pick-up and level sending unit. I plan to add a header tank to the set-up with a secondary pump to fill the header tank from the main tank. That will help avoid sucking air with the tank is low, or on steep inclines.

The bumper itself is 3/16" plate steel, all welded. Boy do I wish I had a brake to bend metal. There are two latches built into the bumper for the tire gate and a secondary "accessory" gate (storage locker, fuel cans, whatever). It's stout using 2 pieces of 2 1/2" square X 1/4" wall steel tubing stacked on top of each other as the main support. That's what the receiver tube is mounted to. The frame is the weak point... again, more pics would be good.

I'm also proud of the T-case mount :)

Anyway, thanks for the kind words!

Thanks everyone. Yes, the fuel tank is behind the rear axle, and fills the space up to the bumper (rubber mounted to the bumper itself). I'll have to get some pics. It's made from 3/16" and 1/8" aluminum, and uses the stock pick-up and level sending unit. I plan to add a header tank to the set-up with a secondary pump to fill the header tank from the main tank. That will help avoid sucking air with the tank is low, or on steep inclines.
Nice Setup! I have a similar ultimate goal as you mentioned (Sportsmobile type vehicle).

I especially like your rear fuel tank. I plan on doing that to my van, too, so I'm glad you filled in some of the details.

But I'm wondering where you put the filler neck... Did you somehow manage to run the filler neck all the way to the stock location?
Since I will keep my stock tank, I planned to put another filler neck in the back somewhere.

BTW - for the interior panels, you can use two-part urethane foam to insulate, stiffen and adhere the wall surface of your choice to the existing vertical framework.

i like it!

Nice Setup! I have a similar ultimate goal as you mentioned (Sportsmobile type vehicle).

I especially like your rear fuel tank. I plan on doing that to my van, too, so I'm glad you filled in some of the details.

But I'm wondering where you put the filler neck... Did you somehow manage to run the filler neck all the way to the stock location?
Since I will keep my stock tank, I planned to put another filler neck in the back somewhere.

BTW - for the interior panels, you can use two-part urethane foam to insulate, stiffen and adhere the wall surface of your choice to the existing vertical framework.

Sorry for a late reply, I've been busy packing for a trip and haven't had much time. I will take pics for you of the fuel tank sometime, but simply, I use the stock filler location. I removed the stock filler tube and modified it, and used a piece of EMT conduit that I bent for an interconnect. The tank inlet is placed on the top front of the tank. It fills fine and works well. I debated about a remote filler, but in the end, there just wasn't enough room (exhaust, rear leaf springs, rear bumper, frame rails, etc are all in the way). I simply extended the stock wires for the sending unit.

I see you have a newer van with the 6 speed trans, so you may not have the problem I did (4L85E). I could not fit a T-case with my stock fuel tank. Maybe it's also a result of the short wheelbase version. Either way, the stock tank had to be removed. I believe the Ford vans have a similar issue, but the tanks are steel, so people cut and weld them back up shorter. Ours are plastic... Even if I could have used the stock tank, the pump and filters still had to be moved. I also cut the trans crossmember and added a hump for driveshaft clearance, right where the ABS and fuel cooler/filters were. Oh, I should mention, I did not reinstall the fuel cooler. I figure that having the big aluminum heatsink of a fuel tank is more effective than the stock cooler ever was (can't confirm that, just a suspicion).

Again, pics would be most helpful to explain a lot of this. I will clean it up when I get back and snap some. Thanks for the recommendation of the foam. I looked into foaming the walls, but am still undecided on the direction I want to take for an interior. Until that's figured out, and wiring is run, I'm hesitant to do anything inside. I may just do a very simple luan/plywood lining (fabric covered) with bubble insulation for now, just to have something. I'm constantly concerned about denting the body any time I put something inside.

Have any pics of your van? What are you starting with (wheelbase? cargo? Mileage?). My van has just over 52K miles on it, approx. 3K after the 4wd conversion. On the freeway, cruise set at 70, towing the jetski's I see ~18.5 mpg. Not towing it's about 19.5. Set cruise at 75, mileage drops to 17. Not bad for a big tall brick tooling down the road.

I see you have a newer van with the 6 speed trans, so you may not have the problem I did (4L85E). I could not fit a T-case with my stock fuel tank. Maybe it's also a result of the short wheelbase version. Either way, the stock tank had to be removed. I believe the Ford vans have a similar issue, but the tanks are steel, so people cut and weld them back up shorter. Ours are plastic... Even if I could have used the stock tank, the pump and filters still had to be moved. I also cut the trans crossmember and added a hump for driveshaft clearance, right where the ABS and fuel cooler/filters were. Oh, I should mention, I did not reinstall the fuel cooler. I figure that having the big aluminum heatsink of a fuel tank is more effective than the stock cooler ever was (can't confirm that, just a suspicion).
I have an extended (155") wheelbase van, and there seems to be plenty of room for the transfer case. But you're correct about the need to relocate ABS module/fuel filter/prime pump/cooler for front driveshaft clearance.

I have an extended (155") wheelbase van, and there seems to be plenty of room for the transfer case. But you're correct about the need to relocate ABS module/fuel filter/prime pump/cooler for front driveshaft clearance.

That should be helpful for you. Mine is obviously the 135" wheelbase. I also desired to use a divorced T-case (NP205), which pushed it back another 12" or so versus what a married unit would have been. If you can get away with simply relocating the ABS (or removing, as I did) and the fuel stuff, you should be in great shape!

My sequence went something like this (after rear springs, shocks and front axle was installed):
1. Remove ABS/replumb brakes
2. Change exhaust to fit T-case and fuel tank
3. Build rear bumper to mount tank
4. Build rear tank
5. Relocate/replumb fuel system
6. Mount T-case
7. Modify trans crossmember
8. Build shifter, driveshafts, rotate rear axle (pinion angle)

I should ask...what is your end goal? Solid front axle? Leaf springs, radius arms or links? Final tire size? Desired lift/height? As you may know, the Duramax engines sit VERY low in the frames (or rather, the engine mounts are very low and create a lot of interference issues). They are also offset to the passenger side ~2". I extended my wheelbase approx. 2" for tire to fender clearance, and axle to oil pan clearance. This required moving the steering box forward too. Change one thing and open a can of worms :)

Unless I can come up with an unconventional hydraulic or electric motor drive setup (which sure would be a lot simpler, except for all the engineering & custom fabrication required) to avoid having to do all the mods required for the conventional setup, I will use a pickup truck IFS.

I didn't know that the engine was offset to the right side.

BTW, I have posted a lot of photos & drawings of the front frame & suspension, here: http://www.dieselplace.com/forum/showthread.php?t=442522

Unless I can come up with an unconventional hydraulic or electric motor drive setup (which sure would be a lot simpler, except for all the engineering & custom fabrication required) to avoid having to do all the mods required for the conventional setup, I will use a pickup truck IFS.

I didn't know that the engine was offset to the right side.

BTW, I have posted a lot of photos & drawings of the front frame & suspension, here: http://www.dieselplace.com/forum/showthread.php?t=442522

Thanks for the link. You have a lot of excellent information on the Quigley IFS conversion. Just knowing what parts get changed is helpful. I considered trying the IFS conversion, but in the end wanted a solid axle. I was considering fabricating a K-member frame to hold everything at the heights/position I wanted. You really need to consider tire size, and figure out axle location from there. The vans have little tire clearance (back of tire to frame) when turned at full lock with stock tires. There just isn't enough fender to cut away for bigger tires. That means the axle needs to go forward with bigger tires. My turning radius is smaller than the stock van was after the conversion. My brakes are also much better (not sure if that's because of the front caliper change, elimination of the ABS, replumbing of brakes, or a combination of the above. Regardless, they are better. I'm working to improve them further...

I would strongly recommend a steering upgrade. Doesn't look like Quigley does anything with the steering, but even my stock 2WD van had serious issues with the idler arm at low miles. GM did/does NOT do a good job with steering on their IFS trucks/vans IMO. The rest of it looks okay.

So, are you looking for a lift? You might want to consider starting with a truck lift kit (used most likely), and working from there. They usually include a cradle to hold the front diff, and have LCA mounts built in. This would allow you to move everything around as needed, and then figure out how to mount after that.

Any plans for the rear (assuming a lift)? I have some custom Alcan's in the rear. They seem to work well after they were modded (original pack main and secondary leaves were too long and hit the rear van body mounts on compression).

Keep up the good work/research. Have any questions, feel free to ask.

Oh, one last thing...are you using CAD at all? Do you know about the GM upfitter website?

http://www.gmupfitter.com/index.html

Lots of good information, diagrams, dimensions, etc on the site. I requested some CAD info, and they sent me some models of the frame, transmission, etc so I could play in SolidWorks. Came to find out, they sent me a 1/2 ton frame model, but it was good enough to get started. You might want to request models if you are using CAD.

The maximum lift I would consider is about a 1" body lift, to allow slightly bigger tires, enough room for 265/70-17 (or at most, 285) on OEM HD pickup truck 17x7.5 wheels.
I'm pretty sure that 265/75-16 tires on OEM 16x7 wheels fits without any problem, and apparently 265/70-17 on OEM 17x7.5 wheels do too:
http://www.dieselplace.com/forum/showpost.php?p=3455123&postcount=11 but "mxzine" hasn't been around in almost two years, so I can't confirm if he had any clearance problems after he made that post. I may be adding a raised roof, and total height matters to me too.

Also, I want to keep things as stock as possible, which (oddly enough) is why I really would rather drive the front wheels with electric gear motors bolted to the inside of the knuckles, but realistically that would be a lot more difficult to accomplish (not enough space, can't protect well enough from road spray, etc.) than the concept seems, and it would be a lot more limiting in operation, too (only useful for short bursts due to limited battery energy available). But I think you can see where that would be a lot easier from the standpoint of not having to make all those other frame/chassis mods. Unfortunately, there is no off-the-shelf anything available to do this.

I have all the PDFs from GM upfitter.
Other drawings, like this one:
http://www.dieselplace.com/forum/attachment.php?attachmentid=125674&stc=1&d=1325395764
I have gleaned from online parts catalogs.

I noticed that my van seems to have the same dinky tie-rods as those on HD pickups that attract so many complaints, but was not aware of any problems with the idler arms?

The maximum lift I would consider is about a 1" body lift, to allow slightly bigger tires, enough room for 265/70-17 (or at most, 285) on OEM HD pickup truck 17x7.5 wheels.

I have all the PDFs from GM upfitter.
Other drawings, like this one:
http://www.dieselplace.com/forum/attachment.php?attachmentid=125674&stc=1&d=1325395764
I have gleaned from online parts catalogs.

In that case I'm not sure a 1" body lift would be useful. It might be painful installing, given the steering shaft arrangement, and bumpers and what not probably won't look right without some work. I'd imagine a plus size tire should fit in there at stock height.

Can I ask why you are considering a 4WD conversion? Most, but not all, the van conversions I've seen are on bigger tires for offroad. With the long wheelbase version, aren't you going to have issues with break-over height? Maybe this is for mud/snow type conditions?

I hope you don't think I'm criticizing, not at all, just curious.

After looking at the Quigley kit more, their pricing isn't bad considering that includes labor. Even the lift kit option isn't too bad price wise. I'm guessing that regearing the rear axle IS included in the pricing, since the diesel van kits cost more than the gas vans ($300 extra), and I don't see any pricing options for that. So, for around $14K a person can get 4WD and 3" lift put on their van, just limited by year of vehicle. Not bad considering the parts are new. My conversion cost more than that so far with used parts, but I do realize mine is very different and more work has been done, and my labor is "free". Mine also includes ARB, rebuilt front axle, coilovers, wheels, tires, fuel tank, etc... it adds up quick!

If doing an IFS...maybe find a complete truck to swap from.

EDIT: Yes, the tierods are tiny. My idler arm was worn out too, and actually would HIT the frame when turning and going over a curb (parking in my front yard). There was a ton of play up front, and it only had ~48K miles. Once I removed the steering, I could really feel the play in the joints. You might want to look into either a brace or upgrade. Maybe mine was just a bad apple?

http://www.cognitomotorsports.com/products/123/Idler_Pivot_Assembly_-_Steering.html?left_select_reset=reset

After looking at the Quigley kit more, their pricing isn't bad considering that includes labor. Even the lift kit option isn't too bad price wise. I'm guessing that regearing the rear axle IS included in the pricing, since the diesel van kits cost more than the gas vans ($300 extra), and I don't see any pricing options for that.
They told me it was another $750 for changing the rear axle gears. The pricing shown on their website is still based on the pre-2010 DMax vans that already have 3.73 rear axle ratio. The 4WD conversion costs more for a DMax than a gasser most likely because they have to relocate the ABS module & fuel pump/filter/cooler.
They also will not use anything but a manual shift transfer case, and they are pretty inflexible in many other ways, too.
They also have to charge about $800 in sales tax on the conversion, or they will deliver it ~35 miles across the state line into Maryland for about $400. That's an expensive delivery charge. I'd also have to drive it to Pennsylvania, and add the cost of staying there for 2-4 weeks while the convert it.
And the more I look into how their conversion is done, the more it seems more like "Kludge-ly" than Quigley.

Lastly, I need to do several other things at the same time the 4WD is added, and that will not happen if Quigley does it.

As for why I need 4WD, you know how easily these things can get stuck, even with a G80 (which mine does have):
http://www.dieselplace.com/forum/showpost.php?p=4467013&postcount=67

It does kind of irk me that (thanks to customer demand, of course) that manufacturers make every type & size of 4WD SUV imaginable, even though those not very useful for hauling much except a few people, but there is so very little availability of 4WD in a van (the GM 1500 AWD van being the only exception, and it has very little payload weight or towing weight capability).
.

They told me it was another $750 for changing the rear axle gears.
The pricing shown on their website is still based on the pre-2010 DMax vans that already have 3.73 rear axle ratio.
They also will not use anything but a manual shift transfer case, and they are pretty inflexible in many other ways, too.
They also charge about $800 in sales tax on the conversion. Or they will deliver it ~35 miles across the state line into Maryland for about $400.

Interesting...their website is quite misleading then in this regard. $750 sounds more realistic for a regear given parts/labor/warranty.

I'd prefer a manual shift T-case personally, but I always do anyways. Maybe they can forego installing the shifter, and you can make your own and place it where you want?

Not sure about the sales tax. I sort of expect that, and it's kind of a drop in the bucket considering everything else. I'd hate to add up all the sales tax and shipping costs I paid over the course of my conversion. Shipping a cast iron T-case from Canada wasn't exactly cheap, but it was easier than sourcing one locally and then rebuilding myself. Sometimes, although rarely to me, convenience outweighs the cost. I did all my own axle work, fab, etc other than the T-case and two of the three D-shafts (I made the short shaft).

Another $800 here, another $750 there, drive 1500 miles, stay 2 to 4 weeks, drive another 1500 miles, it all adds up... to get a kludge with hole in my floor and a shifter right where I need the seat to pivot... and NO other stuff (extra fuel tank, etc.) done at the same time when it was a lot easier to do it.

Many times I've thought I should have bought a 3500 Cab & Chassis (with the full-power Dmax & Allison tranny) and turned it into (essentially) a cutaway, but I ruled that out early on, due partially to the fact that a van's sides are so much flatter than the pickup body, and a van has 2-ft.+ longer cargo bay in the same overall length compared to a pickup, and I didn't want a huge "shoulder" (typical cargo box) sticking out right behind the cab, and the fact that a C&C based vehicle would not be useful to me until I designed, built & installed some type of custom body, whereas my van is useful to me right now. But I just don't see my van being able to tow much up any kind of hill on anything but pavement or dry gravel.

If I do the conversion myself, or have somebody willing to work with me (e.g.: "tdiguy" / Eric) do it, certainly I will utilize a donor HD pickup. That's why I put so many comparisons in the thread I linked: http://www.dieselplace.com/forum/showpost.php?p=4471856&postcount=14 / http://www.dieselplace.com/forum/showpost.php?p=4473101&postcount=20

There's also the still unanswered question about whether the tailshaft in a 2WD version of a 6L90 transmission is the same as the 4WD version:
http://www.dieselplace.com/forum/showpost.php?p=4469074&postcount=12
http://www.dieselplace.com/forum/showpost.php?p=4469106&postcount=13
2011+ HD pickups have a new transfer case & adapter compared to 2007.5-2010 HD pickups.

Another $800 here, another $750 there, drive 1500 miles, stay 2 to 4 weeks, drive another 1500 miles, it all adds up... to get a kludge with hole in my floor and a shifter right where I need the seat to pivot... and NO other stuff (extra fuel tank, etc.) done at the same time when it was a lot easier to do it.

Many times I've thought I should have bought a 3500 Cab & Chassis (with the full-power Dmax & Allison tranny) and turned it into (effectively) a cutaway, but I ruled that out early on, due partially to the fact that a van's sides are so much flatter than the pickup body, and I didn't want a huge "shoulder" (typical cargo box) sticking out right behind the cab, and the fact that a C&C based vehicle would not be useful to me until I designed, built & installed, some type of custom body, whereas my van is useful to me right now. But I just don't see my van being able to tow much up any kind of hill on anything but pavement or dry gravel.

I hear you loud and clear on the costs. Don't misunderstand me, I'm definitely not made of money. I thought long and hard about all of this, and ended up taking the plunge. I already had the tools and ability (welding, metal working, etc). I think it requires a little insanity to take a plasma cutter to a relatively expensive newer vehicle and start cutting. it sure was satisfying driving it for the first time after the conversion.

So now that I have my van built and running, I've also considering going the truck route, for many of the same reasons you cited (full power, allison, etc). Actually, I'd strongly consider a Cummins swap into a newer Super Duty (but what trans?). The truck platform has advantages (tow a goose or 5ther), decent crew cab already done, OTS parts available, etc. I could have thrown a camper on the back and be ready for camping, yet unload and be ready for working. If I went with a newer D'max HD, I'd be looking at doing a solid axle swap too, or at least adding a quality lift and upgrades. Not a cheap route either.

If I was to go the truck route, I'd most likely build an aluminum camper to replace the bed with. It'd most likely pop up (a la Alaskan style), and the top would be removable to reveal a service body. The body would have lots of storage accessible both internal and externally to make use of the space in front of and behind the wheels. It would follow the body shape and not stick out. The down side to this model is overall length. Put an 8 foot bed behind the crew cab, and it's long and would be a pain to get back into places I want to go. The short bed makes getting lumber and steel a pain (van will swallow 10 ft no problem, and 12 foot pieces are okay if narrow).

I go back and forth. The van was an upgrade in volume without additional length over my Suburban. It sits the same height (frame height) as the Burb I had, yet offers alot of internal volume and better mileage. A pop top would make the van much better for camping in. Guess it all depends on the final uses. I'm still on the fence to be completely honest. I really could use both. For now the van works well for 90% of my needs (well, once I get more seats in there). It'll be my deer camp this weekend, all set-up with a cot and everything I need inside, ready to go, locked up and organized. It will also get me back to where I want in the mud and snow.

The van was an upgrade in volume without additional length over my Suburban.
Even a standard length van has HUGE advantage over a Suburban in volume. It's cargo volume rating is about double, but it's really almost triple when you consider the van's much flatter sides, compared to a pickup/SUV.

Suburban/Yukon XL cargo volume with all rear seats out: 137 CF / Length: 102"
Std. (135" WB) cargo van volume: 270 CF / Length: 125"
Ext. (155" WB) cargo van volume: 314 CF / Length: 146"

And of course it's more practical to raise the roof on a cargo van than an SUV, due to the much more pronounced curvature of the sides ("tumblehome") on an SUV.

That's what swayed me too. I wasn't in love with a diesel nearly as much as most of the others on this forum, but I also knew I could not make my own gasoline, but I might be able to make my own diesel. That said, all too often in some parts of the country, diesel fuel is so much higher than gasoline that diesel trucks/vans are not cost effective unless you absolutely need the towing capacity.
Case in point:
http://www.wyominggasprices.com/index.aspx?fuel=A
vs:
http://www.wyominggasprices.com/index.aspx?fuel=D
Granted, this is mostly a winter phenomenon, but still...

Even a standard length van has HUGE advantage over a Suburban in volume. It's cargo volume rating is about double, but it's really almost triple when you consider the van's much flatter sides, compared to a pickup/SUV.

Suburban/Yukon XL cargo volume with all rear seats out: 137 CF
Std. (135" WB) cargo van volume: 270 CF
Ext. (155" WB) cargo van volume: 314 CF

And of course it's more practical to raise the roof on a cargo van than an SUV, due to the much more pronounced curvature of the sides ("tumblehome") on an SUV.

That's what swayed me too. I wasn't in love with a diesel nearly as much as most of the others on this forum, but I also knew I could not make my own gasoline, but I might be able to make my own diesel. That said, all too often in some parts of the country, diesel fuel is so much higher than gasoline that diesel trucks/vans are not cost effective unless you absolutely need the towing capacity.
Case in point:
http://www.wyominggasprices.com/index.aspx?fuel=A
vs:
http://www.wyominggasprices.com/index.aspx?fuel=D
Granted, this is mostly a winter phenomenon, but still...

Oh yes, much bigger, and as a cargo van that's empty in the back, more practical too. My mountain bike can stand-up as well, which takes up much less room than one on the side. I like the platform, just not perfect for everything. Then again, I don't think anything would be perfect as there is a trade-space involved (room, size, cost, mileage, etc).

I did want a diesel. Not too happy with the current cost differences, but I'm still ahead driving the diesel versus my gas Burb (not including purchase price difference). I'm satisfied with the mileage I'm getting out of my van after the conversion. Best I could do empty with the Burb was 14ish, and about 12 towing the jet ski's. I also like the torque of the diesel, which does great offroad. I'd be even happier with an Allison though, and full power. The stock 4L85 is fine, just wish I had more horses sometimes.

So, if your van was 4wd, would it be the right vehicle for you? Or is now the time to sell it and buy a truck? Building a nice bed body is probably easier (more straight forward) than converting to 4WD IMO. Not necessarily cheaper, or less work though.