# GM 8.5 Diff Swap



## 69 242 GTO (Dec 11, 2018)

I have a 69 GTO with a 8.2 Limited Slip and I have a 8.5 Limited Slip from a 1985 Olds 442 with 3.73 gears and the 200 R4 overdrive trans as well.
Has anyone put a 80's 8.5 in their older Pontiac.
It looks like the overall width dimension on the 8.5 are 3" shorter and the shock holes are 2" less.
Coil spring location is the same but the lower control arms are angled in instead of perpendicular to axle.
Thanks for any help you can provide.


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## 69 242 GTO (Dec 11, 2018)

The angle of the control arm mounts don't match up so I went with a 12 bolt.


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## PontiacJim (Dec 29, 2012)

The frames changed as the cars got larger in 1973 and up. So you would have wanted an 8.5 from 1971-72 A-body in order for it to work as a bolt-in.


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