Can a 6.2 or 6.5 Diesel fit in my 1990 GMC Suburban 4x4 and will it fit with my 700r4 Transmission? (GPS, spark plugs)

[Blackandgold51]

I've been thinking about switching from my Gasoline 5.7 350 Engine to a Diesel.v

I'm not worried about performance, just effeciency.

And I plane on keeping my Suburban for a long time if-not long time

Also, what are the true advantages of a Diesel vs Gasoline and am I making the right decision of switching to diesel? Amd are diesels as easy to work on as gas engines?

Another thing, I heard and seen diesel engines having a hard time starting in the cold weather.

I live in New Orleans by the way and the weather is like cold in 50-30 degrees.

Also,I have an automatic transmission.

[GarageLogic]

Don't do it. You will run into hundreds of problems you never anticipated, and you will sink more money into it than a 25-year old Suburban could possibly be worth.

If you want a diesel Suburban, sell yours and buy one that is factory diesel.

[Electrician4you]

Originally Posted by GarageLogic

Don't do it. You will run into hundreds of problems you never anticipated, and you will sink more money into it than a 25-year old Suburban could possibly be worth.

If you want a diesel Suburban, sell yours and buy one that is factory diesel.

This^^^^x10. Adding it all up along with custom fabrication getting ALL the needed parts you'll be dumping 50k in it. Your cost may be a bit less if you find a wrecked truck and buy it whole to have all the tiny little parts you will need. I hope you're a good fabricator.

[Merc63]

If you bought my '94 6.5 turbo diesel truck for $3k, you could do the work yourself and be in it under $5k. But it would be a LOT of work. You'd have to use the engine and transmission together (it's also an automatic, but a 4L80E, the 700R4 won't fit). And you really won't be gaining that much in efficiency. The later Duramax diesels can be relatively efficient, but the 6.5s weren't as good. Great for towing however, which is what I've used mine for.

[scarabchuck]

Don't waste your time with a 6.2/6.5 , put a Cummins in it. There are plenty of conversions done with that. Much easier , especially if you go with a 12 Valve. Years ago at the drag strip we ran into a guy that had a 90's Chevy crew cab dually that had done the conversion, this one had a 6 spd auto. Said he loved it and pulled his 45' gooseneck trailer like nothing.
I've got a Ford Excursion that I'm really considering doing a Cummins swap on.

[whiteboyslo]

If everything is working properly, at the temps you see, a diesel shouldn't have any problems starting. I have a 91 F250 with the 7.3L IDI diesel. When I first bought it, it struggled to start in the artic tundra that is SoCal in the winter (lol). With a new set of glow plugs, it now starts faster than anything I've ever owned (after the GPs cycle, of course).

Mike

[Blackandgold51]

Originally Posted by GarageLogic

Don't do it. You will run into hundreds of problems you never anticipated, and you will sink more money into it than a 25-year old Suburban could possibly be worth.

If you want a diesel Suburban, sell yours and buy one that is factory diesel.

So it's best to just atay with what I got and find parts for my Suburban such as headers, cold air intake amf good exhaust to gain mpg.

[Blackandgold51]

Originally Posted by scarabchuck

Don't waste your time with a 6.2/6.5 , put a Cummins in it. There are plenty of conversions done with that. Much easier , especially if you go with a 12 Valve. Years ago at the drag strip we ran into a guy that had a 90's Chevy crew cab dually that had done the conversion, this one had a 6 spd auto. Said he loved it and pulled his 45' gooseneck trailer like nothing.
I've got a Ford Excursion that I'm really considering doing a Cummins swap on.

But how long does it takes to put in a Cummins and do I have to remove some of the parts in the engine bay in order to put in and operate the Cummins?

And is it simple?

Plus, can it go with my 700r4 Transmission?

[scarabchuck]

Originally Posted by Blackandgold51

But how long does it takes to put in a Cummins and do I have to remove some of the parts in the engine bay in order to put in and operate the Cummins?

And is it simple?

Plus, can it go with my 700r4 Transmission?

I've followed quite a few builds online and nothing really looks crazy tough.. but looking at pictures and standing in a garage looking at the empty engine bay of your truck and a motor on the floor are two different things. I'm sure I could do the job myself and I work behind a desk for a living but where I would run into issues is having the patience to do it.
I don't think a 700R-4 would be up to the torque of a diesel.

Check this link out :
Fordcummins.com - Chevrolet Cummins Conversion Information

[GarageLogic]

Originally Posted by Blackandgold51

So it's best to just atay with what I got and find parts for my Suburban such as headers, cold air intake amf good exhaust to gain mpg.

To be honest, you're never going to gain a lot of mpg on an older Suburban, regardless of how much tweaking you do. Because it's kind of "old school Chevy" there is every imaginable after-market part available. And they're not all that high-priced for what they are. But you have to do some serious thinking about return on investment. Is it worth throwing $1000 - $1500 worth of parts on it, to gain 1/2 to 1 mpg?

My suggestion would be to do a complete tune-up. Don't waste money on "ultra-amazing-triple-spark plugs" or gimmicks like that. Just do new plugs, new plug wires (if needed), new distributor cap & rotor, and do a good cleaning of the TBI.

Then, if you want economy, buy a Kia.