'A' body rear end into a 'B' body
 

Anyone have experience installing an A body 12 bolt rear into a '61-63' B body? Comments? Thanks!

This is going backwords. The 57-64 Olds/Pontiac 9.3" rear end is one of the best in the business. You want to keep the stock rear end, put some new rubber bushings in the control arms and your good to go.. I use to tack the bushings a few times to keep them in the arm..

I kept the Currie built 9 inch from my 68 ElCo for my 63 Cat. The basic width works. Have no real plans other than knowing I'm going to need to fabricate custom control arms at the bare minimum.

You’ll have to change mounting points and the control arms.

Yes, as 389 stated, I'm curious as to why you'd want to do this. 57-64 9.3" Olds-Pontiac rear parts aren't cheap but can be found, and you'll have a rear stronger than a Ford 9". Even the stock 31 spline axle shafts are stronger than Chevy 30 spline.
https://www.markwilliams.com/axles-schmaxles.html

The ring and pinion are bigger than the 9" Ford but the parts are not necessarily stronger. Back in the old days when we were racing a 1962 Cat in Formular Stock Class we split the case wide open. That was with a fairly stock 389.

Wow, so I can put a 61-64 big Pontiac rear end in my 69 el Camino! I was wondering about that, I'd love to do that. I already have adjustable, spherical rear control arms..

Please PM me if you feel like giving me any tips on the swap so's not to hijack this thread.. Thanks!

I wouldn't go that far. It's the approximate width and they are both 4 link, but that's about as close to similar as they get. I'm prepared to do major surgery going in, but I have little to offer until I break out the plasma cutter and MIG.

I'm planning to narrow the rear rails to get them clear of the HUGE wheelhouses, so building new link points isn't that tough once you've gone that far.

I'll take a wild guess here - You're looking for a carrier that will handle the more modern differentials?

Rearend Swap
 

The question is prompted by cost - parts I have onhand vs what would need to be bought to get either setup running.

Specifically, whether the frame mounts would need to be moved if custom control arms had spherical rods on both ends?

Thanks!