Exactly, my guess is that the Monte rear is 8.5, and the Olds is 8.2 BOP. I just want a direct swap into my car and would rather not have to spend any more on parts. If the Monte rear is 8.5 and would bolt right in, would i have to upgrade the axles? Main reason i did on the 8.2 was because of that, its an 8.2. lol