I have a 6.2l Na in my 1986. I pull a 20ft enclosed race car trailer once a week and the NA 6.2 is not enough. I am wondering what my options are to finding more power. I love this truck since its so clean and very little rust i hate to sell her to go to different truck. Can I put a turbo off of a 6.5 or would I be better off swapping the whole 6.2 out for a 6.5 turbo? It also has a 700r4, 2:73 gears, 4x4, 30x9.50x15 and AC.

You can advance the timing by moving the injection pump or turn up the fuel screw inside the pump. Easy things to start with are replacing the fuel filter and the air filter.

As to a turbo charger, see this thread: http://dieselplace.com/forum/showthread.php?t=174571

I have already changed tthe air filter and fuel filter, and when i pull the trucks smokes like a freight train. I was told that the gentlemen I bought it from installed 6.5 injectors in it maybe thats the problem.

if thats not a misprint, the 2.73:1 gears are killing you, the tallest i'd ever want to run are 3.42's, and even lower if u tow a lot.

oops my bad that is a mis print I have 3.73s, 700r4 and 30x 9.50 x15 . I dont have enough power to pull in OD and if I pull in 3rd at 65mph it starts to over heat 220+ so I have to back down to 60 I just need more power so i can pull in od. What about water injection

Water injection will do nothing for you unless you turbocharge it. Water injection cools the charge-air, making it more dense, and allowing you to squeeze more O2 into the engine, maintaining the power lost by compressing, heating, the intake air.

oops my bad that is a mis print I have 3.73s, 700r4 and 30x 9.50 x15 . I dont have enough power to pull in OD and if I pull in 3rd at 65mph it starts to over heat 220+ so I have to back down to 60 I just need more power so i can pull in od. What about water injection


If your pulling that kind of weight, you need 4.10's, those tires are lowering your final drive. Most times, unless you have a turbo, you won't be able to tow in OD. I can't right now but my brothers 97 6.5 TD will tow in OD no problem. You can add headers, free flow exhaust, intake mods etc but best bang for the buck is a turbo system.

i think that towing in OD with a 700r4 is pretty bad for the tranny. but i plan on a dual 2.5" exhaust and turn up th IP, i've heard thats a pretty decent increase in power.

i think that towing in OD with a 700r4 is pretty bad for the tranny. but i plan on a dual 2.5" exhaust and turn up th IP, i've heard thats a pretty decent increase in power.

Whats decent? ;)

Towing in OD is fine if it stays in OD, when it shifts in and out, thats what kills it.

I have already changed tthe air filter and fuel filter, and when i pull the trucks smokes like a freight train. I was told that the gentlemen I bought it from installed 6.5 injectors in it maybe thats the problem.

The 6.5 injectors are different from those for the 6.2. I`m only guessing, but I`d think it`s not a good idea to use them on the 6.2.

As to towing in 4th gear instead of 3rd, I`ve been towing in 3rd with the Tahoe (which had a 4L80E) all the time. Towing in 4th with the 700R4 seems to be something that kills the tranny which was later renamed to 4L60, and ppl keep saying that you must never tow in 4th with a 4L60.

Why do you overheat when towing in 3rd? Do you tow with the converter clutch locked? If not, you could change the setup so that you can lock the clutch in 3rd and generate less heat. See http://www.bowtieoverdrives.com, they have info and wiring diagrams.

Can the 6.5 injectors contribute to the overheating problem?

6.5 injectors are fine...as long as there is some kind of air intake and exhaust mods done first. sounds like it only smokes at WOT so he's ok there...just get and monitor an EGT gauge. a turbo will lower your temps nicely.

my first recomendation would be to stop trying to pull 10k+ with a 6k tranny and 3.73 gears. this can only lead to problems. remember that the 700r4/4l60 is only rated for 6k nominally, and a suburban weighs in at almost 6k alone. a pickup will be a little less, but you get the point.

my second would be to use the od on flat or downhill stretches ONLY, manually shifting it to 3rd for any kind of situation where the pedal is near the metal ;)

you should probably give up the idea of towing at speeds over 65MPH anyway. i know drivers in my area aren't paying much attention to the other people on the road, and a trailer only adds to that. keep it safe...

a turbo will help keep the EGTs down and get you some more power. a 6.5 swap would be great, but not easy. it would probably cost a bit too in incidentals. a 6.5 turbo on your 6.2 would be easier and has been covered here in many threads. a banks or ats turbo kit would be easiest

I just read on the SSD site that they're going to make a turbo kit for 6.2's and non-turbo 6.5's.

I just read on the SSD site that they're going to make a turbo kit for 6.2's and non-turbo 6.5's.

can you pm me a link? i just looked and found nothing :(

If I was towing what you are towing, first change would be install 4.10's. Install 180 degree robert shaw thermostat, modify your fan clutch to engage at a lower temp(this is done by using a cut off wheel and cutting an additional notch in the bracket that holds the thermal spring on the front of the fan clutch. Next would be upgrade to a J series intake manifold and a cold air snorkel to pull air from the front of the truck. Next, replace your factory mufflers with low restriction mufflers. You might also want to check your timing, because you shouldn't be smoking that bad unless someone has cranked your fuel up a lot. Last but not least, turbo the engine, but don't go for maximum power so that you can keep reliability.

That is strange that you have problems towing.
I have standard gears (3.08's I think) and I have towed 6000lb around 70mph with no problem that was before high flow thermostat and all my mods but I was running P235/75?/15 tires then.
It could be those tires you have. I have 31.5 inch tires and have not tried towing since I put them on. But I put the bigger tires on and turned up the IP in the same weekend then went on a road trip right after that. The truck felt like it had more power and got around 24mpg with the new size tires factored in.
Also my trans locks up at about 30mph no matter the gear, my 1985 Z28 is the same way. I though all TH700R4's were that way?
I have a strange truck.

That is strange that you have problems towing.
I have standard gears (3.08's I think) and I have towed 6000lb around 70mph with no problem that was before high flow thermostat and all my mods but I was running P235/75?/15 tires then.
It could be those tires you have. I have 31.5 inch tires and have not tried towing since I put them on. But I put the bigger tires on and turned up the IP in the same weekend then went on a road trip right after that. The truck felt like it had more power and got around 24mpg with the new size tires factored in.
Also my trans locks up at about 30mph no matter the gear, my 1985 Z28 is the same way. I though all TH700R4's were that way?
I have a strange truck.

I don't think its strange, I am maxed out at 65 mph in 3rd towing my 7x12 enclosed trailer, aprox wieght of 3000lbs. Uphills, forget about it.

Hills are bad even when unloaded but I can still get over them. Depending on how much smoke I want to let go I can make it over a mountain near the speed limit but thats going to take 3rd gear, every thing the engines got and lots of smoke.
On level ground can you tow and maintain speed in top gear?
If I locked my truck in 3rd gear 65 would be about the top speed.
I have driven to Maine with my car and truck different times. The car is lighter and has more power. It goes over the same hills no problem, it stays in top gear. The truck strugles to get over some of the mountains in NY and PA.

Hills are bad even when unloaded but I can still get over them. Depending on how much smoke I want to let go I can make it over a mountain near the speed limit but thats going to take 3rd gear, every thing the engines got and lots of smoke.
On level ground can you tow and maintain speed in top gear?
If I locked my truck in 3rd gear 65 would be about the top speed.
PA.

Nope small hills even unloaded are a challenge. Towing any kind of weight requires a heavy right foot.

If your all ready overfueling ie. Black smoke turning up the fuel is not a good idea. And if you are running the 6.5 injectors i am not sure but i think they flow more fuel so maby your overheating problem is related to the overfuel? not sure but thats where i would start:) chuck

I have a 6.2l Na in my 1986. I pull a 20ft enclosed race car trailer once a week and the NA 6.2 is not enough..

You can fart around "till the cows come home" and you're not going to get very much out of any 6.2 without a turbo. I've driven several since new, and still have quite a few. A J-code with maybe 250 ft. lbs. of net torque is about best you can hope for - and that's not very much. That being said, I've done a lot of towing with NA 6.2s, TH400 trannys, 3.73 axles and stock 31.7" tires. I wouldn't consider pulling anything more than 6000 lbs. unless is was in pure flatland with absolutely no hills.
A 700R4 will pull just as well as long as you don't use 4th/OD - but it's not going to be very durable. 700R4 has the same durability rating as the TH350.

6.2 becomes less useful pretty fast once you start running it past 2200 RPM. At that speed, it can't flow much air since it's only got a volumetric efficiency of somewhere around 60%. If you turn up the fuel, it will smoke and get hot. When all is right, it will still get hot with hard pulls on long hills. I haven't towed with any 6.2s with 4.10s - and it would be kind of futile without overdrive for long highway runs. With the 3.73s, 65 MPH is about as fast as it wants to go comfortably. I have a Ford F250 with a 6.9 diesel, three-speed automatic, and 4.10 axles and any speed past 60 MPH gets scary. The 6.9 has 315 lb. ft. of torque at 1400 RPM and is not enough for pulling hills with heavy trailers. Considering a NA 6.2 only has a best of around 250 lb. ft. at a higher 2000 RPM - you cannot expect much. Put a turbo on it, get more durable heads, turn the pump up, etc. and you can get over 300 lb. ft. of torque out of it. A 6.5 won't be any more durable - except for an improved cooling system and maybe - better heads.

Remember the 6.2 is a short stroke to large bore engine - and there's not much you can do to change that. That combo is not meant for torque but does allow for horsepower at higher RPMs. Long stroke - i.e. leverage - is what makes high torque available. If you really want a tow rig - find a long stroke diesel. That's why an 80s 5.9 Cummins in a Dodge can easily make over 400 lb. ft. of torque at 1400-1600 RPM.
A 6.2 is 3.98" bore by 3.8" stroke. A Ford 6.9 is 4" bore by 4.18" stroke - a little better for torque. A Cummins 5.9 has a 4" bore by a long 4.7" stroke - that's what makes torque and pulls trailers at moderate RPMs - especially when used with an intercooler and turbo.