5.7, 5.9 or 6.2

[Ammo_1984]

I was at a friends house a few days ago and told him I was going to go diesel with my 78 3+3.
He has a running 5.7l olds diesel and a 6.2l.
First is from an 83 Caprice and the other from an 82 3/4 ton square body 4×4.
I was leaning toward the 5.9 Cummins.
Now I am not so sure.

What do you guys think?

 

[yevgenievich]

6.2 is simple and will fit with no problems. Cummins will need fab work. Depends on what you are looking for out of the motor swap and that tools/etc available.

 

[foamypirate]

Whatever you do, stay away from the diesel 5.7 Olds. They are a giant heaping turd. They are probably single handedly responsible for destroying the reputation of diesel engines in US passenger cars for 20 or so years...

 

[bucket]

Whatever you do, stay away from the diesel 5.7 Olds. They are a giant heaping turd. They are probably single handedly responsible for destroying the reputation of diesel engines in US passenger cars for 20 or so years...

Yep! Besides being troublesome, they didn't do a single thing well.

 

[68post]

In agree with going above the tiny and much maligned 5.7 Olds , not enough potential without spending a small fortune. But that Olds block is a stronger block than a BBC block, and they're great for building a large ci Olds smallblock from 425 ci to 440 ci !

A Olds diesel "D" block has some issues to check into, but a diesel "DX" block is good to go. A naturally aspirated 350 ci diesel was too small for a truck !

They used a normal and common Stanadyne pump , but "pencil " injectors.
GM was diesel stupid back then.

 

[rollinon35s]

I think it all depends on the big picture for your build. The 6.2 when tuned right can be a dependable motor with fuel economy on your side. The conversion would be much simpler as others have said since it is basically a 350 block it should bolt right in. Depending on what trans you have, with the right converter, it should bolt right up as well. So if your not looking for monster torque it's a good swap imo. With that being said the cummins will require some welding and fab work for sure so the install will definately take some time. The benefit to that extra time and money spent in this case though is the abundance of performance mods available for the cummins as the build progresses. It's hard to beat the torque and reliability of that inline 6 imo. Good luck with whatever you decide

 

[Ammo_1984]

Thanks for the replies.

I have built many great olds gas motors from the 5.7l.

Big picture for my 3+3 is complete frame off restoration with many upgrades including the Cummins.
For now I think I will drop the 6.2l in my truck.
I just need to find a standard flywheel for it and a new clutch.