Hi, I have a 1991 Firebird with a 10 bolt non posi
drum brake rear in it. I want to know if I could put a
9 bolt disc brake posi rear (from a 1987 Z28)in my car and use the
backing plates and the drum brakes from my 10 bolt non
posi rear in the 9 bolt posi rear? Thanks

 

1st let me say welcome to the boards. Why would you want to keep your drum brakes????? Do a search and you'll find a ton of info on the swap

 

The reason that I want to do this is because the guy that has the 9 bolt posi rear for sale is going to keep the backing plates,rotors,brakes,porportioning valve, and the e-brake cables for another rear. The car that this rear is out of is in great shape and only has 76,000 miles on it. He is putting a new rear in his car since he is putting a 383 stroker in it. I thought that if i could use my backing plates and drum brakes that it would be alot cheaper and easier for my car.

 

why dont you just swap the carrier and gears>?

 

I don't think they are interchangeable
9 bolts have a different size ring gear then 10 bolts