# '65 GTO Rear gear ring and pinion change.



## tigervette (Feb 18, 2012)

I'm trying to change the rear end gear from 3.55 to 3.08. I have a 10 bolt rear end(original). I'm confused on whether to order for 8.2" or 8.5". I see both in catalogues How do I know which one I have without removing the cover? Thanks for any help.


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## Pinion head (Jan 3, 2015)

The 8.2 Pontiac is the only 10 bolt rear used in Pontiac A body's until the '73 models came out. If you have an 8.5 A-body rear that someone has upgraded your vehicle with, it will have a fairly large pinion flange with 7/16" headed bolts holding stamped steel straps to attach the rear ujoint. The 8.2's used u-bolts, lock washers and nuts to attach the ujoint.


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