I was wanting to change the gears and put a limited slip in my 72 skylark it is currently a 2:56 open, anyway we have an old 81 Buick Park Avenue with an 8.5 in it. What I wanted to do was remove the the 81's and clean it all up and get everything set up like I wanted then switch the rears on a saturday as the 72 is my daily driver. I just wanted to know if the upper control arms are cast the same on the center section of the 81 as they are on the 72, and as far as the coilspring pads I have a welder and can move them if needed. I also have not measured the rear yet to see if it will fit although I would think it should be very close. Do any of you guys know if I can do this I was just trying to save a little money. I wanted to take my time with the rear rebuild like 3 or 4 weekends so me and my dad could share in it.
if i understand what you want to do correctly.......those rear ends wont swap out.if the other rear is an 8.5 and has a posi with lets say 3.08 gears you could rob the unit and gears from the 81 and install in your rear.......
I crawled under it and made sure it was an 8.5 and a coilspring rear, I figured I could just reweld the spring pads. What I wanted to know was if the upper control arm links on the center section were the same as on my 72 i.e. same angles and bushings .
The positioning of the cast perchs on the '81 ('77+ B series) housing is much wider an angle than on '64-72 A-body rears, so the '81 rear is nowhere near an easy fit. Yes, I've run across guys who've cut & spliced frame sections in, but all were cobble jobs :shock: Another consideration is the B series r/e is slightly wider than '72 & earlier A-body rears, & as you've noticed the shock mounts are inboard. FME, the bolt-in axle '78+ 8.5 B series rears are best used, to swap into '73-77 A-bodys, or to part out. One needs to start with the correct housing. Hope this helps. :3gears: Roger
