I perused everything on here I can find for this but I'm looking for some clarification. I'm doing a pro-touring build on my 66 special. I've got a set of billet specialties 17x9.5 wheels with a 5.5" bs and 285/40's fresh off of my 70 camaro that I'd like to use on the buick. If my math isn't too far off I think width-wise it will all fit with a mild minitub on the 58" wide g-body housing. I read that the lower arms are a bolt up but the upper geometry is wrong. I see where some guys say you need offset arms, others say you need longer arms, and the list goes on. Anybody actually done this without a huge amount of problems? I have a complete g-body 8.5 with 3.73's available to me free and if I save money here is allows me more to invest in other areas on the car. Otherwise I'll just have to buy a built rear for it and frankly, that hurts the wallet! Thanks
I would not bother with that swap. The G-body 8.5" is a great rear,and worth good money to the G-body crowd. By the time you get everything modified and the parts to make it work under your car,you could just get a 71-72 A-body 8.5" and save a lot of hassle.
thanks Brian, I was looking at the overall width being very close to perfect for using my big wheels and not having to narrow a rear, get axles, etc, etc. Kind of a budget pro-touring setup. I figured with the g-body rear being 3-4 inches more narrow it would be about right. Seems that the geometry is a little different but I can work that with a welder! lol
I run a 15x10 with 5.5" backspace,with a stock width rear. If I install rear discs,I could get a 6.00" backspace. It didn't sound like you need a narrower rear with that wheel.
A friend of mine swapped an A body 8.5 under a G body back in the late 90's, and had to have "custom" upper suspension arms and weird offset wheels to get it to work; I would ASSUME that doing the reverse setup would require a reverse setup. Not worth the trouble IMHO. As others have said, the 8.5 G body rear (especially with the 3.73 gears found ONLY in the 83 & 84 Hurst Olds; Monte Carlo SS had the 7.5 and 7&5/8 rears.)
Seems like it would work on a chevelle but my 66 special scrubbed the outer lips with a 275/60r15 on a 7" rally wheel with only 3" to the outside. Factory width 10-bolt on drums. I might try it just to see but I don't want to tear anything up.
I don't own a Chevelle,but since all of the A-bodies use the same frames,the results should be the same for the backspacing. When they were built the wheels were centered in the wheel wells. If you get a wider wheel,you split the difference,going inboard and outboard. That is why back in the 70's and 80's,people got 10" rims,jacked the back of the car to the moon,and everything stuck out the side. They never thought to get a deeper backspace rim.They just ordered a rim with the same backspace as the originals. Can't do that. Mock up what you have and see where you have to go from there.
