Just like the title says, what's the difference? I have a 91 with a 3.1 and then a 84 z28 with a 350 and it needs a tranny so how much would it take to put the 91 in that?

Bellhousings are different, and I think some internals - I've always read that it's possible to make a V6 700R4 work, but no where near worth the expense or the trouble.

700R4's are easily available for $300-$400 used, at least around here.

Yeah its just that I have this car was going to use some other stuff too... Thanks