69firebirdman, I'm not swapping the axles. I have an entire 8.5 rear end. It is brand new and only cost me $600. I priced a posi unit and gears for my BOP and it was going to run me $1200 including labor. I have also heard that the 8.5 10 bolt is almost as strong as a Chevy 12 bolt. I'm not knocking the BOP. It all boils down to $$. This is the cheaper way to go to get where I want to be.