a body rear end swap help needed

[Grandprixpaul]

Need help from you guys that have a a-body rear end swap. Picked. Up a 1973 grand am 8.5. Posi 342 gears. Need to know beside top control arms what do I need to change or modify. If you have a 12 bolt rear can you tell me what your width is back plate to back plate. Thanks guys
.

 

[565bbchevy]

Sorry I can't answer your question but I stopped seeing your car on Craigslist and thought you sold it, I am glad to see you still have it.
The last pictures I saw it looked like you were removing the vinyl top, any updated pictures?

 

[455'ed80Regal]

The 73-77 rears are a different animal than those before and after them and don't know if anyone has put one in a g body or not. I've not seen any upper arms to adapt one to fit our cars either.

 

[Rick_B_86]

The 73-77 rears are a different animal than those before and after them and don't know if anyone has put one in a g body or not. I've not seen any upper arms to adapt one to fit our cars either.

I mistakenly bought one, and it would have been a royal pain making it work. I later found a 70 Monte 10 bolt but I used to spring perches from the 73 as they were the over-the-tube style. Lower control arm brackets would need to be cut, moved and welded (and only a 1/4 inch, but it was enough to cause some bind) the upper ears also sit at a different angle, so even the UMI swap arms don't work.

That being said, anything is possible to do. You could technically make it fit, you pretty well just need custom control arms, a decent welder, time and patience.

It definitely won't be a weekend swap.

 

[Grandprixpaul]

Sorry I can't answer your question but I stopped seeing your car on Craigslist and thought you sold it, I am glad to see you still have it.
The last pictures I saw it looked like you were removing the vinyl top, any updated pictures?

 

[Grandprixpaul]

Started painting and doing bodywork at my job like I went to school for. Going. To finish it just picked up a. Few things I. wanted for it. Seats need to dye them. Holley electronic. Fuel. Pump. And. The posi rear end. Need to modify some things that To make it fit but I have a master welder fabricator at work to help. Thanks for the push to finish I'll take pics as I start to Put together.

 

[Rktpwrd]

Need help from you guys that have a a-body rear end swap. Picked. Up a 1973 grand am 8.5. Posi 342 gears. Need to know beside top control arms what do I need to change or modify. If you have a 12 bolt rear can you tell me what your width is back plate to back plate. Thanks guys
.

I can't speak to swapping in an early A body rearend like that, but I agree, they're a whole different animal. Best to resell that rear and go a different route. I was fortunate enough to find a 12 bolt Chev rear from a '71 Chevelle. UMI 12 bolt swap upper control arms made that part work, but I still had to narrow it, which entails custom axels and cutting off and relocating the lower mounts inboard.
If you can afford it, a pre-engineered F*rd 9" from Strange, Currie, or one of the other mfg's would be the way to go, but at a bit more of an expense. All depends what route you want to go, and how much you want to spend.

 

[Doug213xrj]

I think That the upper control arms have another small bolt hole that is used that needs to be drilled bigger for the control arm bolt for this swap.

Doug