A-Body Rear?

[Turbo5]

Anyone have experience using a A-Body 12-Bolt rear in a G-Body? I know they sell control arms for the transplant but don't know about width of the rear or backspacing issues? Performance Good/Bad? Any other Pros or Cons? Thanks.

 

[Steve]

The A-body rear is wider than a G-body rear so the wheelbackspacing will need to be changed accordinly. If you have a 8.5 rear now the 12 bolt isn't a big upgrade. The internals are not a whole lot heavier and you still have C-clip axles. If you want a bulletproof rear with the 12 bolt you end up buying axles, C-clip eliminators, and a carrier and possibly a gear depending on what the 12 bolt came with and with those upgrades the 8.5 would be extremely stout also. I cut 1.4X 60's on a 130K mile comepletely stock 8.5 for 2 years with zero failures. How fast are you looking to go? If you are not looking to go faster than mid 10's the 8.5 will work great.

 

[turbofish38]

I've done the swap on my GN. Only I used the 8.5 10 bolt from a 72 Skylark. It uses the B-O style that has pressed on bearings like a Ford/Mopar instead of C-clips. It is longer than the stocker so you will need new wheels. I run 8 inch wide DragStars on the strip with a 5" BS with a 10" slick with no rubbing. On the street I run widened stock steels that are 10" wide with a 6 1/8" BS. What I like about this axle is that with the extra length I've also widened the rear track at the same time. Much like what GM did with the 4th gen F-body. It goes around corners like a slot car is about how I would describe the difference. Here is a pic of it with the 10" stockers.

 

[Madcat455]

I used a 8.2 BOP rear (68/9) in my 84 cutlass(it was cheap and easy to get)... about an inch longer on each side, had to roll the lip inside the fender wells to make my 84 Ttype wheels fit with the 275/60R15's.


My lower control arms actually had enough "flex" to use with that rear(never said it was done right..lol)... no sway bar though.

If I did it again, I'd use the lower arm adapters.


Was a worthy swap for my 455 Buick engine in there, 4.10 posi was nice too.

 

[KEVINS]

I've done the swap on my GN. Only I used the 8.5 10 bolt from a 72 Skylark. It uses the B-O style that has pressed on bearings like a Ford/Mopar instead of C-clips. It is longer than the stocker so you will need new wheels. I run 8 inch wide DragStars on the strip with a 5" BS with a 10" slick with no rubbing. On the street I run widened stock steels that are 10" wide with a 6 1/8" BS. What I like about this axle is that with the extra length I've also widened the rear track at the same time. Much like what GM did with the 4th gen F-body. It goes around corners like a slot car is about how I would describe the difference. Here is a pic of it with the 10" stockers.

Eric, I love the look! Very SAWEET!
How much wider than stock is that rear?
What's the wheel and tire combo on the front and rear?
Any other pics?

ks

 

[skylarkstage1]

Please identify the vendor who sells the control arms that allow the transplant of the A-Body rear in a G-Body. Thanks.

 

[Madcat455]

Please identify the vendor who sells the control arms that allow the transplant of the A-Body rear in a G-Body. Thanks.

I found this.. Looks like SSM makes/made them.

SSM #1328

That has the part# on there, but I can't find a web site for South side machine.

I had some SSM lift bars for my 72 GS, but I got them from Summit.

 

[Turbo5]

Please identify the vendor who sells the control arms that allow the transplant of the A-Body rear in a G-Body. Thanks.

UMI Performance has them under the G-Body section...

A-Body 12-Bolt Swap Control Arms

UMI Performance Inc.

 

[Steve]

I believe that Southside Machine is out of business. I know there is a guy on Ebay that makes control arms for this swap. The guy on Ebay is somewhat local to me and though I haven't used any of his stuff I have heard others say his stuff is pretty good qaulity.

 

[turbofish38]

I bought my kit from hpmotorsports.com . Here is another pic for Kevin.

And this thread http://www.turbobuick.com/forums/florida-area/182278-tr-pics-daytona-speedway.html shows the same wheels with some larger 275/60 oval track recaps on it. I'm the third pic on the first post.

 

[TURBOPOWERED68]

What did you do about the drive shaft?

 

[TURBOPOWERED68]

I've done the swap on my GN. Only I used the 8.5 10 bolt from a 72 Skylark. It uses the B-O style that has pressed on bearings like a Ford/Mopar instead of C-clips. It is longer than the stocker so you will need new wheels. I run 8 inch wide DragStars on the strip with a 5" BS with a 10" slick with no rubbing. On the street I run widened stock steels that are 10" wide with a 6 1/8" BS. What I like about this axle is that with the extra length I've also widened the rear track at the same time. Much like what GM did with the 4th gen F-body. It goes around corners like a slot car is about how I would describe the difference. Here is a pic of it with the 10" stockers.

what did you have to do to the drive shaft to make this swap work?

 

[Chuck Leeper]

David, this is a 10 yo thread. I've not seen Eric on here, for many yrs....

 

[TURBOPOWERED68]

David, this is a 10 yo thread. I've not seen Eric on here, for many yrs....

i hoped someone else had done the same and saw the thread.

 

[BMR]

Drive shaft should be fine unless you have a 7.5 shaft. Then it would need to be shortened by about 1.5-2". If the rear is a Chevy, you will need a conversion u joint. BOP used the 3R joint (same as G bodies) back then, but Chevy used a joint with outside clips. I think it was a 1330 style, but that may not be correct.