I've got a friend with a 97 Chevy Monte Carlo with the 3100 V6. He wants to know how much needs to be changed to swap in a 3800. He keeps asking me about it, and it makes me feel stupid. I don't know a thing about Chevy's. Thanks for any info on swapping in a 3800.

You would need the trans, engine, PCM, wiring harnesses, and drive shafts out of a 98 z34!

If you are going to take the time to do something like this you might as well go with a L67 (3.8 S/C)
I have a buddy with this swap done putting down some insane numbers!

Check out L67swap.com that will tell you everything you would need to know!