I would like to swap My current rearend ,,,68 El Cam, (12 bolt,Possi,spicer? 3:90 ratio) with C-Clip Eliminators. What I want is a more highway freindly rearend,,still a 12 bolt possi,,,but with say a 3:08 or 3:31 ratio. What I wanted to know Is...What Year rearends can I use?? I think I read somwhere that 68 thru 72 ElCamino,Chevelle,rear end are the same, and totally interchangeable. Is there any other earlier GM cars that came with the 12 bolt possi rear end,that will work also???? It would be nice to know ,, while searching the wrecking yard. Also does limited slip,, and Possitraction,,mean the same thing? Thanks Guys,,, Joe

All 68-72 GM A body rears will swap. Actually, the 65-67 will also swap, they are just about 1in narrower, so you would need to check your wheel backspacing.
Yes, posi, limited slip are the same term. If you were to run across a super good buy on a 65-72 12bolt with/without posi, it might be good to get it anyway. It would make good trading material. I know guys here are always looking for 12bolts. Aftermarket posi units are available for non-posi rears, so just finding a 12bolt is good, if the price is right.

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Tom Parsons

[This message has been edited by DZAUTO (edited 10-24-99).]

TomDZ, I allways enjoy Your responces! They are informitive and fun to read at the same time. Now I know what I am about to ask IS a bit much mabey ,,,but could You name what cars GM built,,65 thru 72 were "A" body cars? or would the list be too long? I apoligise for My ignorance on this but Im just getting started in the chevelle game OK?i was at a wrecking yard this weekend while out of town and spoted a 70 Monte Carlo that was partially buried in mud! needless to say it hinderderd my beeing able to get under the car and count the bolts on the differential cover. So I guess that is why i am asking if You could tell Me what cars are "A" body cars....is the Monte one of them??????Im on the lookout for anything that will work on our beloved chevelle's now!!! LOL Thanks Again Tintop55

Chevelle
MC
Elky
Pont Lemans/GTO---Maybe Gran Prix?
Buick Regal
Olds Cutlass/442 (may have a different 10bolt from Chev 10bolt which is almost as strong as a 12bolt)
All of the above includes wagon bodies also.

When you look at a rear end, look at the bolts at the bottom center of the cover. A 12bolt will have 2 bolts at the very bottom, like this .. and a 10bolt will have one . at the bottom center. No need to count, you can spot the diff in a heartbeat.

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Tom Parsons

DZ Auto Tom,...I read You loud and clear now!! :) Thank You!!! Tintop55