Building an M37 need some engine swap input

[suprathepeg]

Just starting a M37 project.

Truck has been sitting for over 20 years, motor is shot so we're gonna replace it with something more modern with more power. We have several options and I'd like some input on what is the simplest and overall most satisfying to drive in modern traffic and the occasional off road adventure.

The truck is going to run on 80s Chevy 1 ton running gear (D60 & 14B)

The options that are within reach:
454 with a 700r4
5.3 LS with a 4l80e
Late 80s 350 TBI with a turbo 350
5.9 cummins

I think we will do a divorced NP205 t case.

Thoughts?

 

[Maple Leaf Eh]

Hey mosquito swatter! There might be enough space in the engine compartment, but don't build something that the brakes will have trouble stopping or the suspension holding up.

The Canadian M37 had a bigger engine that the US model. So, sadly unless you can find a stash of Canadian parts, you are probably doing the best you can for the old girl.

 

[shadow9er]

Suprathepeg, I'm getting ready to do a rebuild very similar to yours. I'll be following this thread with much interest. I currently have an 88 Chevy 3500 1-ton that I can strip for parts...complete running gear and power-train (454 with 700R4). I'm undecided whether I should go with this setup or try for the 5.9 Cummins... Anyway, good luck to you.

 

[Maple Leaf Eh]

....

The truck is going to run on 80s Chevy 1 ton running gear (D60 & 14B)

The options that are within reach:
454 with a 700r4
5.3 LS with a 4l80e
Late 80s 350 TBI with a turbo 350
5.9 cummins

I think we will do a divorced NP205 t case.

Thoughts?

I have never touched a drivetrain swap anywhere near this scale, so my points are not fully informed.

To learn a little more about these things, I goofled the engine and transmissions you posted. One thing that jumped out was the electronics for some later vintages of the 700R4 transmission. If I understand electrical harnesses, you are going to have to wire just about every component again, and then start tracing faults. A lot of modern vehicles have stops, warnings and switches everywhere that need to be in the correct sequence for things to fire up. You can't just snip and terminate unneeded wires; that wire might be to a door lock or a parking brake actuator, and closed (or open) circuits are needed or things won't run.

 

[suprathepeg]

I think were going to use a late model 6.0 and 4l80e from a late model GM 2500/3500.<br><br>The only real questions we need to address are transfer case and rear diff. If we end up with a 2wd donor than a divorced setup is pretty straight forward, if we find a 4wd donor, it looks like the front driveshafts some out on the wrong side so we will need to figure that out.