Dad just bought a 95 2500 chevy with a 6.5. It runs decent for a 6.5 but were already looking to put his engine out of his 91 in it. Its a 2wd. Anyone done this? Know what problems we may run into? I was also wondering if it would require a standalone ecm for the trans?

 

Yea the trans will require a stand alone ECM because its a 4L80E.

Why not swap in a 5 speed?

 

I've done it once, not really too bad, just need to mock it up right and measure twice, cut once, that year engine is dead simple to wire. I can't say too much about your trans I used the NV4500 and just changed input shafts and was good to go, feel free to PM with questions or take a look on the cummins conversions page, there are a couple good write ups there.