GM 6.2 diesel swap questions

This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.

I

Irish52084

Joined
May 4, 2009
Threads
25
Messages
166
Location
Puyallup, WA
So after lots of research, I'm torn between 2 diesel swaps for a 60/62, 6.2 gm diesel or Isuzu 4bd1/2T. I think it will be less expensive to swap a 6.2 than an isuzu, but I thought I'd defer to expert opinion on this so let me know what you think and tell me if I'm missing anything.

6.2 Swap list:
$2000 Military blazer or diesel truck, whole and running strong
$800 advanced adapter 700r to 4spd x-case
$200 Jt outfitters engine mounts, might be able to use donor mounts
$200 x-case rebuild kit
$800 rebuilt 700r with torque converter
$500 For the little extras that pop up
$4500 for the complete swap

Maybe I can offset some of these costs by selling the donor truck for parts, th400, transfer case, dana 60's and such. Plus, I'll have a fj60/62 transmission and engine to sell. I'm hoping in the end I can sell some parts get my swap cost down to $3500. Does this seem realistic or am I making some major miscalculations?
 
Forgot to add a few possibly important pieces of information.
1. This will likely be my daily driver
2. I'm not a great mechanic, but i have taken an fj40 completely apart, including dismantling and putting the frame back together. i just cant weld or fab pieces and don't have access to a lift or press.
3. If anyone knows what mileage I should expect I would love to have your input. I'm hoping for 16-18mpg city and 20+ highway.
4. Last but not least, I forgot to wish everyone a happy thanksgiving.:doh:
 
I think before you spend a dime you should PM me your name and mailing address for a freebie V8 instruction manual. The only prices I disagree with on your list are the motor mounts and the 700R4 adapter to split case. Possibly PM me for some enlightenment on those items!!!
 
i think b4 you do this conversion you should ask lots of aussie's on forums that have done this conversion if they are happy with the power, fuel econmy,overheating probs and slowness only advantage i think you have is cost here they seem to start @ $15000 for this conversion
 
What is your specific target vehicle, the 60 or 62???

After reading your posts, I believe you want to run an automatic, is that correct? The reason I'm asking is that it is possible to run the 6.2 ahead of the 4 speed, if you are OK with the final drive ratio.

the 6.2 is the best bang for the buck. Other members can weigh in on the liters/kilometer, but I believe the 6.2 is better balanced and quieter than the 4 banger.

Rick
 
After talking to the :princess: this morning, she will be a part time driver of the diesel cruiser, she would greatly prefer a 62 or 80 for the power options and more family friendly set up. Personally I like the 80 over the 62 for looks and that really cool sliding rear window for the dog. I happen to have a couple good choices for 62's so that's why I asked more specifically about the 60/62 swap.

I used a few calculators to get an idea of my rpm's a various cruising speeds and a transmission with OD seems to be the best option. I'd like to have an nv5600 or nv4500 but the 700r4 is cheaper and provides the same overdrive. If the swap goes cheaply enough I would definitely go for the nv45000/5600, I love shifting my own gears and the little lady doesnt mind driving a manual.

I will probably add the banks turbo kit to the swap as well. I've heard that the 6.2 responds really well to a turbo and some marginal gains in MPG's can be had.
 
Would there be any real benefit to running and intercooler for the 6.2? I haven't really seen anyone discuss the possibilities or what real world gains are achieved.
 
Now that you are considering the 6.2 and adding a turbo, take a look at the 6.5L. This subsequent motor has the turbo factory fitted, block strengthening and the accessories all run on a serpentine belt, making a much nicer package.

If you are not in a hurry, you will be able to purchase a rusted or wrecked running truck for the same price as the 6.2L.

I agree, the 80 series with a 6.5L swap is the pinnacle of value conversions! If you get into a real operation of the conversion, share the experience with us!

Rick
 
The only reason I didn't consider the 6.5 turbo diesel is because it was only available as a fully mechanical system in the 1993 model year. I guess I could convert to a mechanical system.

The banks turbo kit was sold as a factory option on civilian 6.2. I have read a few reports that claim the banks kit on the 6.2 is actually better because the 6.2 is a lower compression engine.

The overall cost of a factory 6.5TD would probably be less expensive and the serpentine belt system would be a major plus.

Did the block strengthening only occur on the 6.5 block? I thought I read somewhere that GM strengthened the blocks in 1988, but I don't remember if that info is correct.
 
Irish52084 said:
Would there be any real benefit to running and intercooler for the 6.2? I haven't really seen anyone discuss the possibilities or what real world gains are achieved.
Click to expand...

There's no point until you're running over about 12psi boost. Not many people appear to run much boost on those engines without major work.
 
I know it probably totals your budget, but the Optimizer 6500 is worth looking into. It's the new, updated 6.5 diesel with stronger block, internals, etc. It's available brand new from an AM General subsidiary as a replacement engine for the Humvee and other Gm trucks, with or without turbo, your choice of injection system, etc.

See here. Google should pull up some owner stories/discussions on other diesel boards, like this one.

It's also known by its casting number, P400, so that search term also helps if you want to do any internet digging.
 
Irish52084 said:
The only reason I didn't consider the 6.5 turbo diesel is because it was only available as a fully mechanical system in the 1993 model year. I guess I could convert to a mechanical system.

The banks turbo kit was sold as a factory option on civilian 6.2. I have read a few reports that claim the banks kit on the 6.2 is actually better because the 6.2 is a lower compression engine.

The overall cost of a factory 6.5TD would probably be less expensive and the serpentine belt system would be a major plus.

Did the block strengthening only occur on the 6.5 block? I thought I read somewhere that GM strengthened the blocks in 1988, but I don't remember if that info is correct.
Click to expand...

It appears you have been doing your homework!

Don't be afraid of computer controlled injection. Yes there are a few more pieces to fail, but there is a lot of upside after you are up to speed on the systems in and outs.

I can't answer about the blocks, but I do remember the 6.2 has some stuff available to strengthen the block bottom end. I think it's aftermarket, but again I am not sure.

If you can get over the hump of the learning curve, the programmable 6.5L is the best value.

Rick
 
You can outfit and older 6.2 with the manifolds and turbo setup from a 6.5 TD- do a search for diesel place.com and look in there for 6.2 info, differences in heads (some are prone to crack... I would even pot up in there and get their response. They helped me out a TON and there is VAST knowledge about the 6.2s avail after I have owned quite a few of the old beasts...

With that said I don't mean to pee in your cheerios, but I would not do either swap- I would look for a early model cummnins mechanical 6bt with an intercooler for your swap- about the same costs and a TOM more things to do to them for performance cheaply, lots of cheap parts and you will not that the 6.2 diesel guys oftern get tired of them and swap to the 6bt. Just my 2 cents and worth checking into before you pull the trigger! Keep us posted with what you do-
 
also what about exhaust? I once spent $600 on a nice twice pipe 3" setup that you could stand on the end- bomb proof! as far as adding some extra expenses.
whatever you do you probably want to go through the gaskets and the IP/starter/waterpump rebuild while doing the swap while its out- and may need a custom radiator$$$
and power brake booster options...
 
Thank you Dougal for answering my intercooler question.

acy76, thanks for the 6500 optimizer idea, I hadn't thought of them. I've heard of them but never did much research.

rchalmers3, I will do some research o the programmable 6.5. I was taught to work on modern cars and diagnose problems with obd systems, but it's been some time and many of those skills have left me. Are they as plug and play friendly as say the vortec system? If so I might just look into that at my #1 swap on the list.

DieselFumes, I didn't know the 6.5 turbo system was easily swappable to the 6.2, thanks for enlightening me.
I would love to do a 6bt, mechanical, swap, but I am concerned about the cost of obtaining a cummins. I have also been told that the 6b's torque would likely destroy stock landcruiser rear ends. Any idea on how hard it would be to make a dana 60 or maybe 80 fit a landcruiser? Axle length and center differential would be the first concerns I would have. What transfer case options would I have with a dana center diff?

Sorry for the long post and all of the questions. I'm not very knowledgeable about diesels, so I'm trying to learn as much as I can from quality people and this place has been great source of information for me. Thanks for all the info and advice.
 
Exhaust is a good point, I forgot to add that to the list.

I'm definitely going to replace gaskets and check on the IP, water pump and starter. If the diesel comes out of a military truck I have to convert a few 24v solenoids to 12v anyway, so I'll have some work to do.

Thinking I'll run the GM hydra boost for brakes.
 
I have run across some great deals on craigslist on 2wd 6bt cummins trucks that have around 200K on them, even with 300k if you plan on going over some items and the truck runs... you have a lot of your swap. as far as getting it running and then you can scrap the truck, hell you may even be able to salvage and narrow the rear if needed for your truck. Most of the dodges rot off of the motor with the motor still going strong, so with a lil patience and a thoughrough search I think you can find a good candidate- just don't tell the seller what you are going to do, they may not want you to do that to their old workin friend :) I saw a few trucks with a lil over 200K go for $1800-2800 down here in FL, even military/govt/state surplus may have some cummins running through the block.

As far as the power goes and blowing up the rearend... I think a lot of that is how you hammer the pedal and where you hammer it, you can also adjust the IP for a lil less power but why? MORE POWER!!! I used to run 400hp 400lbtq in a jeep with a dana time bomb stock rear and I ran that for years- back in those days I was hard one the throttle but also remembered that if I grenaded the rear I was limping home and had to spend $ to swap in a 9" that I had waiting for the bomb- never ended up exploding the stocker and tried 1 or 2xs! even sold it for $150!

I am sure that you can beef up the stock axles with quality parts, as far as the transfer case goes, I am still new to toying with the offset rear axles in these toys... maybe someone else can privide some light on that.

Check out some specific 6.2/6.5 and cummins forums, I think it will allow you several days of knowledge reading and help you make your decision.

GO CUMMINS!!!! IMO
 
I know a guy who has a 62 with an early 5.9 cummins, no intercooler with a NV4500. With propane he says he has gotten 28mpg.. It is stuffed in there and he has airbags on the front axle. He ran the A440 behind it for a while but the ATF got too warm when he was towing his 20'+ ocean boat!!!!
Keep in mind that many have begun conversions and never finish them- I've seen some here on 'mud and some on E'bay.. The halfcuts look like a pretty good deal when you start thinking about how all the stuff is there-afaik..
 
I've done this swap into a 60 series, and the feedback here is excellent. If I did it again, I'd do a 6.5TD, because it's designed for a turbo, and you can boost it accordingly. The 6.2 is a higher compression engine and was designed to run naturally aspirated, and the 6.5 is lower compression and works great with the stock turbo.

The 6.2 can only handle 10psi of boost, but the banks turbo is designed perfectly for it. I used a banks 6.2 kit on mine, and it turned out nice. My only complaint was oil usage, because the oil could not drain properly using the banks oil drain. I ended up making a drain directly into the oil pan, and that made a difference. If you're doing this swap, then you will be money ahead if you change all the seals before installing the engine - they're known to be leaky engines with tonns of oil loss.

The 700r4 adapter should only cost you 500$ - I paid 450 for mine, but that was NV4500 to split case.

You will need to update your calculations on the "Random items" at least quadruple it. If you plan on using the stock brake master cylinder, you'll need to make sure you have a good vacuum pump ~150$ at the junkyard. I paid 400 for exhaust, that was from the left bank to turbo, and turbo back with 3" pipe. Don't forget about a good shifter ($100), t-case rebuild is 130 from marlin, tranny mount from AA, all new belts and hoses, custom power steering hoses, lots and lots of battery cable (mine had to be installed in the trunk), new fuel filters and water separator, etc etc etc etc etc etc etc etc...

The 80 series is a great choice, because of the suspension system. You should eliminate the stock T-case though, and go with a split case from a 60. That AWD system is a mileage robber.

I averaged 18mpg's with the turbo, and that was city/hwy driving mixed. My cruiser sadly was just sold though on craigslist for 10k to a guy in Colorado.
 
I think before doing any engine conversion, you need to have a good long think about what you are going to use the vehicle for, and what you really want and expect from the conversion when it has been completed.

I did a 6.2 into an '84 60 back in July 2000.
I knew exactly what I wanted from a conversion, and was (and still am) happy with the 6.2.
This conversion needs to be done properly to get the right results.
 
You must log in or register to reply here.

Share this page

Back
Top Bottom