Impala Rear Swap

[CutMonRegMan]

I have a wreck impala ss that i currently am striping down to put the lt1 and 4l60e in my 1985 Buick Regal. I really want to put that limited slip rear end in my regal. Does any body know if the impala rear will fit my regal hub to hub. Has this been done by anyone before because i would really appreciate the help.

 

[85 Cutlass Brougham]

Too wide. Only a G body 8.5 will fit a G body without any modifications. You would have to cut down the housing, have the axles shortened and weld LCA and spring brackets on in the appropriate positions to fit. The Impala SS also has a 5 on 5 bolt circle as compared to the G body's 5 on 4.75 BC. If you use the wheels off the Impala, it won't be an issue if the backspacing works, but you need to re-drill or replace the axles and rotors to make the change. Also, the B car LT1's A/C compressor will hit the frame in a G body. Use Y body ( Corvette) or aftermarket accessory drives to retain the A/C.

 

[CutMonRegMan]

Too wide. Only a G body 8.5 will fit a G body without any modifications. You would have to cut down the housing, have the axles shortened and weld LCA and spring brackets on in the appropriate positions to fit. The Impala SS also has a 5 on 5 bolt circle as compared to the G body's 5 on 4.75 BC. If you use the wheels off the Impala, it won't be an issue if the backspacing works, but you need to re-drill or replace the axles and rotors to make the change. Also, the B car LT1's A/C compressor will hit the frame in a G body. Use Y body ( Corvette) or aftermarket accessory drives to retain the A/C.

Where would i begin to look for axles or would come out better selling the impala rear and put it towards a gn8.5?

 

[pose_442]

In the long run, I'd think you'd be better off selling the Impala unit and find an 8.5 from a GN or a '84 Hurst Olds/ '85-'87 442.

It's a bolt in and the worst case scenario would be to replace stuff that would wear out anyway.

 

[85 Cutlass Brougham]

By the time you have axles made ( $300 or so), get new rotors ( $50-100) and cut the housing, weld on the brackets, etc. you will not save enough money to be worth your time. Plus, if you get it wrong, you have created a piece of scrap metal where once was an axle you could have sold for $200-600 ( depending on the market for the Imp axle). G body 8.5's go for $600-1200 depending on who's selling it and what it has in it.

 

[CutMonRegMan]

7.5 0r 8.5

By the time you have axles made ( $300 or so), get new rotors ( $50-100) and cut the housing, weld on the brackets, etc. you will not save enough money to be worth your time. Plus, if you get it wrong, you have created a piece of scrap metal where once was an axle you could have sold for $200-600 ( depending on the market for the Imp axle). G body 8.5's go for $600-1200 depending on who's selling it and what it has in it.

This will be a everyday driver but i do want to get loose with it every now and then will i be waistin my time to convert my 7.5 to 3:73 posi unit

 

[husky100]

I thought the same thing about my 7.5. Installed some aftermarket axles, Eaton Posi, extended wheel studs, and I run 10.40's. Now grant it I am not whacking it with a trans brake as that would be just flat out stupid!! I do have some 8.5 A body rears with upper and lower control arm mounts and coil spring perches. @55" flange to flange. Also have a built 7.5, if your looking.