I have a 73 Z/28 with a 3.73 limited slip differential. I'm putting a 700r4 trans and would like to move to a 3.08 limited slip with disc brakes. Can anyone tell me which GM vehicles have a compatible size rear-end?

Certain late 70's Trans Am's come with the disc
brakes in the rear. You might want to look for one of those. If your real lucky it will have the gears your looking for too!