Hello everyone. I have owned and driven a 6.5 mechanical n/a engine for about 2-1/2 years now, and, all in all, I've been pleased with it. It's in a '75 1/2 ton with converted 14 bolt rear end truck, and I have never towed more than a few thousand pounds with it.

I just bought a 8,000 lb backhoe. which will come to about 11,000 lbs with my trailer. I plan to keep my truck but also get another one with a dump bed, so I can work with this backhoe. I've narrowed my choices down to two: Get a new duramax dually cab and chassis with a dump body and forget about it. Or get a '86 chevy one ton converted dually that I've got my eye on, put a dump bed on it, and drop in a 6.2 -- either a good running take-out or a new gm factory crate engine. In the second scenario, I'd be using a TH400 and 205. I figure the second option will end up costing about $12k-$15k plus my time versus $40k+ for the new truck. I'd prefer the older truck if it makes good practical sense.

So will the 6.2-TH400-205 combo hold up towing around this backhoe over the long term? Is there anything else I should consider? Thanks for any help.

I just bought a 8,000 lb backhoe. which will come to about 11,000 lbs with my trailer. So will the 6.2-TH400-205 combo hold up towing around this backhoe over the long term? Is there anything else I should consider? Thanks for any help.

Simple answer is "no." You're talking about a truck that's going to weigh 5000 - 6000 lbs. pulling another 11,000 lbs. with 150 horsepower and 240 ft. lbs. of torque and probably a little less because of your altitude.

If you drive on flat-roads only, you might get by. First hill you have to climb you be doing 25 MPH (maybe) with the pedal to floor and the heads getting good and hot.

I've got a 8000 lb. Ford 4000 Industrial backhoe, a 9500 lb. Case backhoe, and a Pettbone 16,000 lb. backhoe. My best 6.2 diesel tow-rig can barely handle my lightest hoe on the flat roads with a T400 trans and 3.73 gears. My 94 Ford F250 with 7.3 turbo and 4.10 gears does a lot better - but I still would not call it comfortable on hills ( 395 ft. lbs. of torque and 190 horsepower).

I also hired a guy recently to move my 9500 lb. Case hoe 120 miles up into the Adirondack Mountians. He had a triple-axle gooseneck trailer and a 2000 Ford F350 7.3 turbo with 500 ft. lbs. of torque and 235 horsepower. He made it, but said he would NEVER do it again.

with your second option, the 86 dually, drop in a cummins 6bt 12 valve instead. it will cost you more than dropping in either a 6.2 or a 6.5, but has alot more power potential.

Find a good used duramax with around 100k on it for about half the price of new and lots of good miles left in it.

Find a good used duramax with around 100k on it for about half the price of new and lots of good miles left in it.

Well, If you see a regular cab, dually, 4x4, 137" wheel base Duramax for sale anywhere in the U.S. let me know please -- I haven't been able to find one anywhere.

I was reading over a post of your's about when you moved to Wyoming and hauled a 10,000 lb (IIRC) trailer with a 6.2 no problem. So why would I have trouble hauling my backhoe with a 6.2?

with your second option, the 86 dually, drop in a cummins 6bt 12 valve instead. it will cost you more than dropping in either a 6.2 or a 6.5, but has alot more power potential.

I have considered a 6bt-NV4500 combo, but I was hoping I could get away with 6.2-TH400 for to save money and time. The truck I'm looking at already has the TH400, so I'd be way ahead. But if I do go with a 6bt, then What do I need to do to it to get the necessary power? I guess the 12 valve engines make about 160-180 hp stock. Or is it just more able to handle the stress? Thanks

I have considered a 6bt-NV4500 combo, but I was hoping I could get away with 6.2-TH400 for to save money and time. The truck I'm looking at already has the TH400, so I'd be way ahead. But if I do go with a 6bt, then What do I need to do to it to get the necessary power? I guess the 12 valve engines make about 160-180 hp stock. Or is it just more able to handle the stress? Thanks

The torque is the main issue, not the horsepower. The Cummins have 400 - or- 430 -or- 460 - or - 505 ft. lbs. of torque at 1600 RPM, the GM 6.2 has 240 or 248 lb. ft. of torque at 2000 RPM.

Yeah, it will pull it. Any engine will pull it, actually... You could put a 10 HP Kohler single cylinder in there and it would pull it, but the top speed would be about 3-4 mph... :rolleyes: It's all about how fast you want to go and how hard you want to work the engine.

If you don't mind going fairly slow and being the last one up a hill you could probably get by with a 6.2/6.5 for a long time, but something bigger with a turbo would be better suited to the job.

I can say this... You wouldn't be the only one to do it. People have been towing stuff that is way to heavy for one of these trucks ever since they came out. You'd be much happier with something more powerful, though...

Yeah, it will pull it. Any engine will pull it, actually... You could put a 10 HP Kohler single cylinder in there and it would pull it, but the top speed would be about 3-4 mph... :rolleyes: It's all about how fast you want to go and how hard you want to work the engine.


It can be more complicated than that.

It's not that simple with a three-speed automatic 2WD. You can take a 6.2 diesel with a TH400 trans. and a 3.08 axle. Hook a 11,000 lb. trailer to it - drive up a steep hill and stop. Then, try to get started again - you can put the pedal to the floor - and - is will just sit there and heat up transmission fluid and make exhaust smoke - i.e. it won't move. In fact, many older 2WD Chevy trucks with TH350s - and NO trailer hooked behind - won't move on a steep hill if geared high.
I drove a few brand-new late 70s Blazers like that. No big deal though - as long as it's a 4WD. You just put the transfercase into low-range and away you go. I had a farmer-neighbor who bought a brand new 79 K5 Blazer with a 350 gas engine and TH350 trans. We crammed six people into it, and he tried to show us how well it climbed steep fields. Well - got half way up - and it stopped. Would not move any further unless put into low range. It may of had a 2- something axle-ratio - I don't recall.

The TH400 has a first gear of 2.48 to 1. The low power of a 6.2 and moderate stall-speed of the converter can make a "no go" situation - depending on the axle ratio and weight hooked behind.

I've even had that problem with my Ford diesel with 4.10 axles. I cannot back up a steep hill with a heavy trailer in high-range. I don't know for sure what the ratio is in reverse with its 3-speed C6 trans. - but I DO know it won't go. Converter just heats up, and the engine twists so bad from the engine mounts that the fan-blades start rubbing against the radiator shroud. Put it in low-range and all is fine. But - if it was a 2WD, I'd be screwed.

Getting away from the TH400 and it's relatively high 2.48 first gear, things get better with the TH350 at 2.52, 700R4 with 3.05, and man. trans. like NV3500 with 3.49, or better yet - the HD SM465 that has a 6.55 to 1 first gear, and a 3.58 to 1 second gear.

For me, I'm more concerned about stopping than going. Driving a 6000 lb. truck with a 11,000 lb. trailer behind you, down a steep hill can be very dangerous. Your life is the hands of the trailer-brakes working properly. If they fail, and you have a light truck, your brakes will almost instantly overheat and you have no way of stopping.

Some vans were fitted with a cummins/TH400 combo. If you dont mind that the engine gets tilted 6* from the adapter plate I think that finding one of those adapters in a junkyard would be perfect for what you want.


An auto tranny also has the advantage of the torque converter and its torque multiplication. But I do agree that you're going to want some low gears in the axles, as low as you can find.

I wouldnt recomend the TH350, 700r, or the NV3500, as they might not be heavy-duty engough for what you are asking them to do. They'll work but probably not for a long time. The SM465 is good and tough but I hear you loose a lot between gears, so that might not be as good eaither.

Some vans were fitted with a cummins/TH400 combo. If you dont mind that the engine gets tilted 6* from the adapter plate I think that finding one of those adapters in a junkyard would be perfect for what you want.


Yes, the TH400 (more specifically the TH475 version) is an incredibly strong transmission. Just lacks range when used in an "all around" vehicle. Stick it up against a 4.56 or 4.88 rear and you can pull just about anything - but your top speed is quite limited. Gear it for highway cruising and you're screwed in first gear for heavy pulling if you have a 2WD. I guess that's why GM upgraded it and made it into the 4L80E.

I drove a Class A motorhome with a TH400 trans. with a Gear Vendors overdrive - and that worked very well. Just expensive.

For me, I'm more concerned about stopping than going. Driving a 6000 lb. truck with a 11,000 lb. trailer behind you, down a steep hill can be very dangerous. Your life is the hands of the trailer-brakes working properly. If they fail, and you have a light truck, your brakes will almost instantly overheat and you have no way of stopping.


Thanks for pointing that out. I guess that is something I should take into consideration. I have a new trailer, so I should hope the electric brakes are good, but it does seem a little sketchy to be putting your life in their hands. I suppose a rear disk brake upgrade would be a bare minimum essential thing to do. But even still is it stupid to pull a backhoe with a one ton truck?

I would have 4.10 gears and 4wd, and I'm not concerned about speed -- I'd mostly be pulling the trailer around town and up into the foothills where there are some steep grades, but it's no problem to take it slow. I have an SM 465 in my current truck and my concern with that is the spread between gears -- particularly granny and 2nd. I think starting on a hill would be a clutch smoking affair.

This whole discussion and the lack of new Duramax trucks with the specs I want available tomorrow (when GM's 0% supposedly ends) had me looking at medium duty trucks today. I test drove an FL70 with air brakes and that was eye opening. I've never driven a truck that big. I'm going to post some questions about it and the medium duty line up over in the medium duty section.

Thanks for all the help. I'm still considering this 6.2 thing, so keep the comments coming.

I pull a pipe trailer around at work everyday with my 6.2 sm465 np205 combo. I have 4.10 gears and 35" tires and it pulls fine other than it can take a little longer to get to highway speeds. My truck with tools ways roughly 7500 to 8000lbs. and the trailer ways anywhere from 8000 to 10000lbs. so hopefully this will give you an idea. My worktrailer also has no trailer brakes so if you have brakes on yours that would make a considerable difference. I also turned up the ip 1/8 turn and 2 1/2 duals into homemade 3 1/2 stainless stacks.

I pull a pipe trailer around at work everyday with my 6.2 sm465 np205 combo. I have 4.10 gears and 35" tires and it pulls fine other than it can take a little longer to get to highway speeds. My truck with tools ways roughly 7500 to 8000lbs. and the trailer ways anywhere from 8000 to 10000lbs. so hopefully this will give you an idea. My worktrailer also has no trailer brakes so if you have brakes on yours that would make a considerable difference. I also turned up the ip 1/8 turn and 2 1/2 duals into homemade 3 1/2 stainless stacks.

K20s came with 6800 or 8400 GVWR packages. If your's is the heaviest made, and it weighs 8000 lbs. - then it has a legal payload capacity of - 400 lbs if it's the heaviest K20, and if the lighter k20 - it's already 1200 lbs. overweight. Then, add your 10,000 lb. trailer - and put 10% of that as "tounge-weight" on the tow-vehicle - and you've got an extra 1000 lbs. That puts the 6800 GVWR K20 2,200 lbs. overloaded - and it puts the heaviest K20 with the 8400 GVWR 600 lbs. overloaded. In my area - if they caught you - they'd either impound your vehicle, or fine you and make you unhook and/on unload.

None of the K20s have enough brakes - even with the heaviest that was available - to stop a 10,000 lb. trailer coming down a hill. In fact, even if you HAD the brakes - you lack the traction to stop if on a wet paved road, or a dirt road.

At least you've got the manual transmission so you have some capacity to hold the vehicle back in a low gear. But, if 2WD, you'd lack traction on a wet road coming down a steep hill. With an automatic TH400, there is NOT enough holdback in 1st gear, regardless of traction.

I don't know anything about the area where you live - in regard to road conditions, flat or steep, or about highway law enforcement. I know where I live, in a rural hilly area of New York - you'd probably get your vehicle impounded if caught. Besides the overload, a 10,000 lb. trailer is not only required to have brakes on all axles, it's also required to have "break-away" brakes.

Granted, on a flat run - you can pull just about anything, with just about anything. I pulled my 12,000 lb. bullldozer - on a 3000 lb. triple-axle trailer with my 87 6.2 diesel Suburban. But, it was for one mile - on an absolutely flat paved and dry road - and at no faster than 20 MPH - and I had all trailer brakes working.

In regard to your K20 and trailer - weighing all-together 18,000 lbs. and no trailer brakes and driving at highway speeds? You are putting everyone else's lives in danger whenever you go down the road. It's one thing to take your own risks - but from what you describe - you've got an accident waiting to happen.

I've seen people load these trucks so heavy and overweight it is ridiculous. In my area overweight mid-'80s chevys aren't exactly on the top of the most-wanted list for running overweight so you can pretty much load them as heavy as you want... It's fairly common to see one of these things loaded really heavy around here so nobody pays much attention as long as the load is strapped down tight and doesn't look like it is going to fall off.

I've found the brakes plenty adequate for heavy loads, but I must admit that a little more traction wouldn't hurt... Then again, I'm running some fairly thin tires so maybe some wider tires would do it.

I've found the brakes plenty adequate for heavy loads, but I must admit that a little more traction wouldn't hurt... Then again, I'm running some fairly thin tires so maybe some wider tires would do it.

What brakes have you found adequate with that kind of load???

Give some specifics. Truck, what brake system, load, etc. I'll buy them and install them.

Sounds to me you never tried coming down a long hill with a heavy trailer with no brakes. If you did, I doubt you'd ever do it again.

I've driven a lot of HD and LD trucks with trailers. Ball hitch, pintle, gooseneck, fifth wheel, etc. I won't bother to mention 1/2 tons. With heavier pickups - in the 3/4 and 1 ton classes - I've never driven one yet that has brakes that can hold back a 10,000 lb. trailer, coming down a hill, for maybe more then 10-20 seconds.

Last year, I lost all my trailer brakes - driving my 1994 F250 turbo-diesel Ford. It has the heaviest tow and brake package available (1 ton package)- 4600 lb. front axle and 6,084 lb. rear axle. Brakes all around the same size (a little bigger) you can get in the heaviest Chevys. This truck was custom ordered to pull a goose-neck four-horse and livestock trailer. I was coming down a long hill - with a 2000 lbs trailer loaded with a 5400 lb. truck on it. When I lost my trailer brakes - I lost most of my truck brakes in 15 seconds - and that was with pumping them in attempts to keep them cool. I'm lucky that it's a 4WD - because 1st gear would not hold it back in high-range. I put it into low-range, 1st gear - and then the engine was over-revving. It was a toss up - if I'd get killed, blow my engine, etc. I just barely made it to the bottom - and by that time - I had NO brakes whatsover. Ten minutes later, they cooled off enough I could drive again. All that with a loaded trailer weight of 7400 lbs. If I'd had a backhoe on the back, I'd either be dead - or - I might of driven off the road intentionally before my speed got too high.

Now with Chevy 3/4 tons - the brakes are going to be the JD6 or the heavier JD7 systems. A JD7 - is about the same as the heavy Ford system. JD7 uses 13" x 2 1/2" rear drums and 12 1/2 inch front rotors. Ford uses 12" X 3" rear drums and 12 9/16" front rotors (but with bigger pads than the Chevys).

And - a note about traction. A guy tried to delivery a tractor to my farm last summer. I live on a steep dirt road. He had a Ford F250 - hooked to a ball-hitch trailer with a 4500 lb. farm tractor on it. Total trailer and load around 6500 lbs. His truck was 2WD and he had NO trailer brakes. His truck would not pull the trailer up my hill - so he went the long way around and came down my hill - very slowly. Well - when he got close to my house - at around 10 MPH, he tried to stop - and couldn't. Trailer just kept pushing him - and with his brakes locked - he had no steering. So, he had to keep letting off of them to keep from crashing. Soon, the brakes overheated and did not work at all. Luckily, he had a four-speed manual trans in granny low - but the rear tires kept slipping. I had to run along side of him and kept throwing pieces of firewood in front of his wheels. We never did get him to stop - he had to ride it out - for a 1/2 mile and landed in someone's front barnyard down the road. Had someone been coming up the road at this time - he could of killed somebody.

I didn't mean without trailer brakes. Trailer brakes are an absolute requirement for any load that heavy on a hill...

I didn't mean without trailer brakes. Trailer brakes are an absolute requirement for any load that heavy on a hill...

Some of my comments are in reference to the guy on this thread pulling a 10,000 lb. trailer - with no trailer brakes - with a K20.

How's the braking system on the new one ton dually trucks? And how is the allison tranny at slowing down a load?

If, on the other hand, I go with the older truck, what is the absolute most bomber aftermarket braking system I could go with?

How's the braking system on the new one ton dually trucks? And how is the allison tranny at slowing down a load?

I don't know much about the specifics with the newer Allisons. But, the farmer nearby to me bought a new Chevy Duramax and Allison combo for towing. The Allison trans. has some sort of special trailer-towing mode - and it holds back real well on hills. He loves the truck for towing - but otherwise says it's a hog on fuel. He says - when empty he cannot get better fuel mileage than 14 MPG at 65 MPH. His older 93 Dodge Cummins was getting 20 MPG with the same empty driving. But again, for towing trailers - he loves it.

He says - when empty he cannot get better fuel mileage than 14 MPG at 65 MPH. His older 93 Dodge Cummins was getting 20 MPG with the same empty driving. But again, for towing trailers - he loves it.

I don't expect to do much highway driving. I also have been told (by a dealer, so take it for what it is) that the engine takes approx. 25,000 miles to reach maximum fuel economy.


I may have just scored a D-max with dump bed at the 0% deal. Just need the financing to go through. . .

I don't expect to do much highway driving. I also have been told (by a dealer, so take it for what it is) that the engine takes approx. 25,000 miles to reach maximum fuel economy.

I may have just scored a D-max with dump bed at the 0% deal. Just need the financing to go through. . .

My neighbor was told exactly the same thing by his dealer. And, he now has 55,000 miles on it - and the fuel mileage has not changed one drop.

But - I've heard a lot of different reports with the Duramaxs in regard to fuelmileage - and who knows how accurate they are. I just met a guy that traded in his 2004 Duramax (and loved it), and just got a brand new one - and says it gets nowhere near as good mileage as the one he traded in - and he's thinking about trying to get it back. I've met Duramax owners that report up to 21 MPG empty - and others never doing better than 13 MPG. I guess you could say the same with all trucks - regardless of who makes them.

I wonder whether the widely varying mileage claims could be due to whether or not the engines were broken in properly.

When I moved from Texas to Oregon, I pulled a pretty heavy U-Haul trailer full of huge record collections, tools, and God knows what else behind an 87 van with a carbed 350/THM400 combo. We got here, but at 40 mph sometimes with downshifting on some of the steeper grades. And this was the less hilly El Paso to Albequerque to SLC to Boise route. Average economy was, oh, 6.5 or so MPG.

Wonder how my 88 Short Bus with the NA 6.2l/THM400 combo would fare with a similar load ?

I do recall reading in the shop manual that the later 6.2s such as mine had different specs on the pre-cups and injectors...they were meant to dump much more fuel down in there, at a cost in MPG.

Does that mod for the air intake with the dryer vents really help out that much with these ?

I don' live in a hilly area and 95% of my driving is in the oilfield on gravel roads or on mud roads. My truck has been upgraded to the 1-ton dana 60 instead of the dana 44 and rear disc brakes so that helps a lot. I do not drive over 35-40mph and yes it has come up at work to add brakes to the trailers because it is extremely dangerous and now they are adding them. On my personal trailers they both have brakes on them. I was simply stating that the truck should pull his backhoe fine as long as you aren't too worried about getting there real fast.

Thumbmasher,

I have towed some pretty heavy loads cross country with 6.2's and 6.5's. I wouldn't recommend towing a backhoe with a n/a 6.2. Could it be done, yes, but it wouldn't be very enjoyable. The first problem is the turbo 400. Great transmission, but they eat horsepower. An sm 465 4 speed will put a lot more power to the ground. 2nd, you need a turbo! I have towed back hoes with one ton dually 6.5 turbos with manual transmissions and they did relatively well. The reason I say don't tow a backhoe with a 6.2 is the same reason I would say don't tow one with a 350 gasser. You need the power level of a 454 to do the job right and a turboed 6.2 has the torque of a 454. The next thing I would suggest is to take your backhoe and trailer to a scale and weigh it. I think you might be surprised that it might be closer to 14,000 lbs than 11,000.

That being said, the Duramaxes are awesome! I own 2, a 2001 crew cab 4wd and a 2002 crew cab 4wd. Both have the allison auto and both get around 20 mpg empty. I also drive a new 06 LBZ Duramax at work and it gets over 21 mpg empty and has lots of power. Yesterday I towed our dump trailer loaded with 4 yards of road base and it accelerated very well. In tow haul mode, the allison helps slow the load very well with very little brake input. As for fuel mileage, I know of several trucks that don't get the mileage they should, but with all of the sensors in these new engines and the computer controls, there are lots of reasons for pour fuel economy. The duramaxes seem to get the best average fuel economy of the big three. I am a cummins fan, but I know of several 05's and 06's that are only getting 13 mpg, and when I swapped out my 300 hp 6.5 for a cummins in my 1985 suburban, I never saw an increase in mileage over what my 6.5 got.

:agreed:

Have a 1981 Dually w/ 6.2 hooked upto a 18' gooseneck (approx 10K) - this truck is completely gutless going uphills (even small ones), to the point that you need to get some real speed up prior to starting uphill. Unhooked - :eek: HOLY Smokes !!! It wants to go and go and go .....it'll EASILY do 100mph.

My 2000 C6500 w/ cat - that's another story ..... the torque is incredible, you hardly know the trailer is there.

2007 Duramax - if you want torque AND speed, this is the truck then.

Best of luck in your search

Ah, this is agonizing. . .
Financing went through on the D-max. It would be $700 per month with the dump body, taxes, everything. I can easily swing that payment.
But I guess the biggest concern for me with the new truck is putting my fortunes entirely in the hands of GM and the dealer. With the older truck, if something goes wrong, I fix it. I might loose a few days of work and put in some long nights in the garage, but I'm in control. The horror stories I hear about new truck problems and weeks of down time while the dealer waits for parts or tries to figure out what's actually going wrong scare me. (Granted, GM is the best choice of the three, but still these engines are so incredibly complicated that inevitably some are lemons.)
When I need the truck to make money and pay off the loans on the equipment, weeks of down time will literally bankrupt me.

What do you all think of a 4 speed, 6.2 with a small turbo, wide open intake, and maybe even a manually controlled water-meth injection system to help keep things cool if nothing else.

Speaking of keeping things cool, I replaced the radiator on my 6.5 this summer when the old one sprung a leak. The rad is small -- for a 350 I think because that is what was in the truck before and what the mounts are set up for (I use a aftermarket transmission cooler for the oil cooling lines off the engine) This winter, I couldn't get the temp above 190 deg no matter how hard I drove it (granted it wasn't loaded, but I was running it at high rpms with the 4 speed and 4.10 gears). Finally, I completely blocked off the radiator and oil cooler with a piece of rubber epdm roofing material, and now it will actually get above 200 deg. Just mentioning this because it seems that there's ample cooling potential for these engines.

When you turn the fuel up and add a turbo to these engines, the hd 4 row diesel radiator is barely adequate and it is at least 30% larger than the 350 radiator.

That being said, if you can swing the deal on the new truck, you should be able to just use it for quite a while without the headaches of being broken down at all and if you have a problem, you are already on a forum with the best info and help anywhere;) Your biggest concern will be how long your rear tires last:p:

The way I see it, if you are going to spend $40,000-$50,000 on a new truck for your business it had better work. That's what they are made to do. Not saying that there is no way it will break down, of course; obviously some percentage of all new vehicles will break. If it does break it is covered under warranty so the repairs shouldn't cost anything, but I know what you mean... When your truck is down you aren't making money.

Your choice. I think the new truck would probably be the best thing for the job, mainly due to the reliability and the warranty, but it is expensive. If you get an old truck, keep in mind that there will still be downtime for repairs and repairs will probably be needed more frequently. There's no warranty on an old truck. For a business I think your best bet is a new truck.

That said, I personally wouldn't buy a new truck from any of the major manufacturers unless it was for business purposes only. There's been WAY too much cost-cutting lately for my taste. Too much imported plastic cosmetic junk. The new vehicles look good, feel good, drive good, and they get the job done, but there's something to be said for a simple, rugged, steel pickup truck. When I buy a truck I want one that has a real bumper. Then again, this is from somebody who has never owned a brand new vehicle...

Ah, this is agonizing. . .
What do you all think of a 4 speed, 6.2 with a small turbo, wide open intake, and maybe even a manually controlled water-meth injection system to help keep things cool if nothing else.

if the land is very flat like it is here in midland texas (elevation in the county varies by a max of 50 feet from the top of the tallest overpass to the bottom of the deepest ditch) then that setup would work, just dont expect to keep up with traffic pulling a 14k pound load.

if i was in your situation, needed a truck to pull that kind of load, had some money up front, wanted simplicity/reliability that when something did break i could fix it on my own with a short downtime, i personally would go with the 80's truck and put a 12 valve cummins in there. minor mods it can easily pass 650ft/lbs of torque that the d-max has stock, is a very reliable engine, simple design as well. if your never going to go highway speed than an sm465 and 4.10 gears would work great (heavy duty clutch would be needed for the cummins), or if you get to 70mph at times go with an nv4500, or nv5600 that came behind the cummins 6bt in the dodge trucks. 1 ton axles are needed (of course with this kinda load/power), and your front suspension will need to be beefed up.

Well, thank you all for the input. Today I put aside my reservations and went ahead and signed my life away to GMAC :rolleyes:

I won't get the truck for a couple of weeks because they are going to switch out the flatbed that is currently on it for a dump bed that is on a gasser. But I did get to drive it today. It is sweet. Basic work truck package, but with cloth seats which helps take away that new plasticy feel and gives it just the right amount of comfort without being unneccessarily plush. I also like the "classic" (pre '07.5 body). I guess I never paid too much attention, but I think the GMC's body style is slightly different than the Chevy's. It's very simple -- not at all brash like some of the others.

Anyway, it was purely a dollars and cents decision and I agree with the previous poster's comments that brand new only makes sense (at least for me) for a business. I'm looking forward to getting it, and I'll still be hanging out here in the old beater section, 'cause my '75 isn't going anywhere. In fact, I'm going to use it to haul fuel and whatever else.

Cool! Let us know how you like your new ride:)

Well, I think you'll love the new truck... You will, of course, have to post some pics of it when you get it...

:cool2:

I have pulled with a 84K5 blazer 33's and 3.42gears, 23K on a two axle trailer, with brakes. Pulled it just fine. it was in town, and never over 50mph. just from one side of town to the other on surface streets. but tobe honest other than increased stopping distance I didn't much notice it back there.
A few months ago i made an out of town trip, up into east Texas. Used the 96 6.5tahoe, 4x4, stock tires and whatever gears it came with. Pulling a 4,000lb trailer, with the blazer mentioned above on it. ran across the scales, and total weight with all the camping stuff and spares was 18,500. with 2k tongue weight. The part of east Texas i went was north of Lufkin, just slightly hilly. No problems dragging it as fast as it was comfortable, ran up to 75 for a bit to catch some guys ahead of me, but mostly ran between 65 and 70mph. stopping withthat rig was worse than the other way round, but it is doable with good trailer brakes on all the axles, not just one. All in all i would say do it, maintain your equipment and be careful.

My old '83 standard cab long bed 3/4 ton truck had a 6.2. I towed a 763 bobcat with bucket on an 18' dual axle trailer.
Traveled approx 15 miles on fairly level roadways. I never went over 45 mph just because I was not sure how it would handle the weight. It could go over that but not much more.
I believe that this load was the max for this style of truck. For safety and performance measures.