I've got a 1970 GS 455 with AC, non-posi/open rear end with a 2.93 gear (ring gear part #1382741, 41-14 GMC). It's the original rear end and still bolted under the GS. I also have a complete axle assembly from a 68 Buick 8.2 posi with a 3.42 gear (ring gear part #1382744, 41-12 GMC). I know I can swap-out the complete axle assemblies but can I just swap-out the internal components? Everything on the original 70 GS rear end has been rebuilt or is new. 1) Can both of the components be removed and then swapped-out or the only other way is to remove the original rear end assembly and put in the 68-rear end assembly? 2) If I can just swap-out the components, what else do I need to do? Thank you
The 68-70 Skylark/GS rears share the same internals,so you could swap them,BUT you still need to set the gears up correctly to make sure they have the exact same wear pattern as they do right now.
Better to swap the whole rear ...I did that when I was racing the monte and had 3.31 rear and a 4.10 rear both 12 bolt chevys. Did not take long to swap a whole rear 1 hour on a good day when i was young. Jim JD Race
Both rears have bolt in axles. That makes swapping the entire rears much easier. Pull the axles of both rears. Then wire up the backing plates, brakes and all. Unbolt the control arms, and swap the rears. Reinstall the axles with the original backing plates/brakes and you are done.
I may be a little confused here, but I think the point of this is that he wants to keep his numbers/code matching rear housing in his 70 GS, but also get 3.42 gears. To keep his car all numbers matching, then he can't swap axle assemblies. If that is not a concern, and the exterior condition of the housings are similar, then I agree, swap the entire axle assembly. My 68 GS 400 ragtop has a 70 GS 350 rear under it, with the 3.23 posi.. JW
iF- this person does not do rear differentials...You are risking ruining the gear set by swapping into another housing. It will all need to be reset-up. SWAP THE ENTIRE rear...Keep the other rear as the Number matching to the side..... drive the 12 41 ...3.42 for the fun of the gears If you are not a concourse car.....(which this would be an entire MOOT conversation) do not worry about it...NO ONE is going to look at the numbers on the rears even in a standard local show. IF it is condition you are concerned about.... I still would just keep the rear whole, clean it up as nice as you can and run the entire different rear for the gear ratio.... If there are SNOBS out there that are going to cut your car down because the rear is a bit crusty looking and you are going to be bothered by them...I would not hang out there. Kind of your decision as we can all tell you what we would do.... BUT it is all you Think it through before ripping up 2 complete good running diffs.
Jim, we are now going to power coat and swap out the rear end. We will be replacing the axle bearings. Do you know the part # for that 1968 8.2 (3.42) posi rear end or who to purchase them from? Thank you.
aS bRIAN SAID, yOU CAN NOT JUST UNBOLT AND REBOLT INTO ANOTHER HOUSING LIKE AN ALTERNATOR OF CARBURETOR ETC. just WAY MORE TO IT THAN SWAPPING PARTS. Oh man sorry for the caps... Jim
