5.7 to 6.2 diesel engine

[p-a71]

Hi Squarebody guys !

I'm new on the forum and I'm here because I plan to buy a new project : a 79' GMC c1500 Hig Sierra Diesel.

This is a factory 5.7 diesel with a th350, air conditionning and power windows.

The current engine is dead, the crank is broken.

I plan to swap it for a Detroit Diesel 6.2 c-code with a th400.

I've few questions about this swap.

What I know ? The motor and transmission mounts have to be differents, the th400 is longer than the 350 so I have to relocate the transmission mount.
The exhaust are the same.

Is it correct ? And about the fuel line ... Do you have some informations with this ? I think some of you have ever made the swap here, do you have the adress about that ?

Thanks a lot ! Pierre-Antoine

 

[Grit dog]

Never done the swap, but mechanical diesel is a simple swap.
Have you considered keeping the turbo 350? Less work to install, and being a 79 it may be a lock-up converter. Think that was first year for that.
I gotta believe a good th350 will run a long time behind a 6.2 in a cruiser truck. Or even a work truck.

 

[p-a71]

Oh yes, I didn't think about that but it can works ! Good idea, if the bolt patern of the 6.2 fits with the th400.

 

[Rickf]

Does the th350 have the BOP bell housing pattern?

 

[Matt69olds]

Swap in a 455 Olds!! That is the EASIEST swap.

Keep the frame mounts. There is a market for them.

 

[p-a71]

Does the th350 have the BOP bell housing pattern?

I think it's a BOP pattern because the 350's block is an oldsmobile ... On the 6.2 I think it's a different bolt pattern ?

 

[Blue Ox]

6.2 has a Chevy bolt pattern. Transmission will have to be changed too. THM400 is a much better transmission anyway.

 

[Big Ray]

Oh yes, I didn't think about that but it can works ! Good idea, if the bolt patern of the 6.2 fits with the th400.

It does.

 

[Strick]

I’d put in the 6.2/400 combo and ride. You will probably need to do some driveshaft work as well when doing the TH400 swap though. Your swap tranny is probably a fixed yolk and you may have to use a 2 piece shaft if the truck is a long bed.

Strickland

 

[p-a71]

Yes I think I've to change or modify my driveshaft. Thanks !

 

[p-a71]

Hi guys,



I just inspected the truck !



So for the body, it had rust on the bottom of the 2 front fenders, on the bed side, on the left door and just a floor cross member . So it's pretty solid, the frame and the cab is ok !



For the mecanic the gmc stayed in a barn during last 20 years so I had to rebuild all the brakes and suspension components.



The sellers give me a 6.2 detroit diesel with 50 000mi on it to make the swap to have a reliable truck !



I just started to look about the price of the parts but I think I'm going to buy this pretty cool SquareBody ! What do you think ? Stay Tuned

 

[Strick]

What do you think ?

That looks like a pretty solid ride. I'm working on an '82 K1500 6.2 right now myself. I love those ole Detroit's.

Strickland

 

[Wallace6]

What is that rectangular thing directly above the speedo an fuel gauge?

 

[squaredeal91]

^^^^Probably glow plugs and water in fuel.
Big Yellow has that

 

[Wallace6]

Do you think that's factory ? Mine was a diesel but I don't see anything with a flashlight lol