B body 8 3/4 into an A

Yes, an A-body rear end ideal, but I'm having a hard time finding one close. I got 2-3 b body rear ends I can look at, so I figured I would just use those. I think I read I need to move the perches in 1/2in on each side, and use some offset rims with 4.5 backspacing. Not sure if this was info from a swinger style though.