Hi All, I have the opportunity to get a rear axle from a 70 GTO, will the 3.55 gears work in an axle from a 71 GS?? Thanks, Adam
Hey Adam.Is your present diff a 10 bolt?? If it`s like mine (chevy style) the closest ratios available are 3.42-3.73.Anyway,you need the 3.90`s to run me :moonu: :laugh: Later,Tony.
Adam, I'd venture to say the 70 GTO has the 8.2 whereas the 71 GS should have the 8.5. (but RIV73 has seen otherwise in another post) If you're getting the whole diff from the GTO then swap in the complete unit. Just a suggestion. If it is in ready to use condition that is. This way you can set your #'s match rear aside. This way if the GTO rear breaks or you don't like the gear ratio you can always reinstall your GS rear or freshen it up while its out. :TU:
Hi Tim, Thanks That is what I figured. The GTO rear is an open carrier and my original GS rear is a 3.08 posi, I wanted to combine the two to make what I feel is a better combo. Tony...... Don't start :moonu:
What??..me start??? Look who`s talking!!! :laugh: I am here to help if you need it in some fashion :TU: Later,Tony.
Don't combine things. Nothing will fit. Just buy a new set of gears for your original. Save you time and aggravation in the long run. 3.55 gears are easlily obtained for the Gm corporate rear the Buicks used in 71-72. Richmond Gears and I think Motive Gear all make them. The Guy that rebuilds rears that I know tells me he does not like used gears or swapping them around as they will not wear correctly. Anyway you look at it, it is going to cost at least $500 to do it right.
Hey Adam, How about having a pro put a posi and new bearings into the GTO rear while sticking with the 3.55 gear? Just another thought. About a $900 thought.....or sell the GTO rear for alot more than you bought it to a Pontiac enthusiast and use the extra cabbage towards a 3.42 gear set up in your GS 10 bolt. It is the stronger axle afterall.
Hi Tim and Dave, Thanks for the input, I think I will just get rid of the GTO rear and rebuild mine as suggested. The axle was given to me so i have passed it on to someone else who can use it. thanks Adam.
My GM catalogue does not show a 3.55 for 71 & 72 GS`s with a 10 bolt (must be aftermarket) Later,Tony.
8.5's never used 3.55's. Market the 3.55's, if they're nice, as used '70-72 PONTIAC 8.2 gears, these took lh thread ring gear bolt & even the carrier is different than earlier '64-69 8.2 Pontiac rear. Got Posi? :3gears: Roger
