Update my drivetrain?

[orbitup]

I bought a pretty rough 69 step not long ago. The previous owner had stabbed a Pontiac 400 with a bad tranny in it. I took it to a friend's shop and he's telling me it may take 900 to rebuild.

I wasn't real hip on the 400 anyway so I have been thinking of other options.

I work in the car auction biz, so I thought maybe I could buy a wrecked newer model Chevy and cannabalize it. That might help me do a disc brake conversion too.

Would this be a good way to go?
What year model range would work best?

I used to do paint and body work so I don't have a lot of experience in this area, but I have friends that could help.