Yet another rear axle fitment question?

[79elky454ss]

I know I cringe at seeing the endless rear end questions, but here goes anyway. What about the previous generation GM midsize cars A-body I guess 1973-77, they seem to be 8.5". How different are they?

 

[pontiacgp]

here's a listing for rear ends...

http://www.carnut.com/specs/rear.html

I was looking for an rear from 64 to 67 Chevelle since it`s 2`wider but the rear and the gears are not that easy to find at a decent price so I`m going to put ford 9`` together since there are plenty around and they are easy to modify

 

[stomis]

I know I cringe at seeing the endless rear end questions, but here goes anyway. What about the previous generation GM midsize cars A-body I guess 1973-77, they seem to be 8.5". How different are they?

I believe they are 8.2" ten bolts not 8.5 if I remember correctly. Also I've read the upper control arms are very limited in travel before binding unless you go to an adjustable arm.

 

[pontiacgp]

I know I cringe at seeing the endless rear end questions, but here goes anyway. What about the previous generation GM midsize cars A-body I guess 1973-77, they seem to be 8.5". How different are they?

I believe they are 8.2" ten bolts not 8.5 if I remember correctly. Also I've read the upper control arms are very limited in travel before binding unless you go to an adjustable arm.

the ears are at a different angle which causes binding if stock uppers are used. There is an adjustable upper that is sold that compensates for the angle..

http://www.umiperformance.com/catalog/i ... nt3q5hm2b7

 

[79elky454ss]

Thanks all, I already have a 7.5 with Auburn posi and I bought 342 gears and install kit for it. I just saw a 75 Monte at pull-a-part which made me rethink my plans. Probably not a significant enough upgrade to change my plans.

 

[pontiacgp]

I just blew up the pinion gears on a 7.5 auburn posi. I`m going to rebuild the auburn and sell it cause it`s not a posi that will take very much power. I am running less than 400 hp and have not really abused the auburn but the pinion gears have alot less meat on them than the pinion gears of an open carrier. I never realized that till the auburn gears blew up and saw the difference in the size when installing an open carrier that I`m using for now.

 

[79elky454ss]

I just blew up the pinion gears on a 7.5 auburn posi. I`m going to rebuild the auburn and sell it cause it`s not a posi that will take very much power. I am running less than 400 hp and have not really abused the auburn but the pinion gears have alot less meat on them than the pinion gears of an open carrier. I never realized that till the auburn gears blew up and saw the difference in the size when installing an open carrier that I`m using for now.

I realize the Auburn is a pretty lame choice, but the price was right (it came in a frame I bought) It should get me rolling for awhile.

 

[pontiacgp]

I never heard any bad things about an auburn and mine worked great till it exploded..I got it used so I don`t know what abuse it was already exposed to and I am also running a standard so that put a little more strain on it as well.

 

[stomis]

I am also running a standard so that put a LOT more strain on it as well.

Fixed

I would go for the 8.2 and ditch the 7.5 for some cash.