Thanks for the info! I already have an A-body 8 3/4 under it, I just need to change the centersection. I see posi's with gears (complete centersections) come up from time to time, and was just wondering if they are pretty much a bolt-in.
The 3 different case numbers will bolt in your housing. You may run into different yoke sizes, but that can be fixed with a conversion u-joint or by swapping the yoke.