a-body rear fitment

[megaladon6]

will a 8.5in rear from a a-body fit an 87 monte ss? i found a good deal on one from a 72 gto.

 

[85 Cutlass Brougham]

Not directly. I think that Southside Machine makes or used to make a set of control arms to adapt an A body rear to a G body, so you may wish to check with them. They are probably best known for their lift bars for 5.0 Mustangs and leaf spring cars.

 

[81malibag]

A-Body axle into a G-Body chassis

To install a 12 bolt car axle, all you have to do is re-drill the the hole on the upper arm 3/4 inch (in) on center. Do this on the bolt hole that bolts the arm to the rear end housing. Napa Auto Parts sells a U-Joint to adapt the combination. Good luck.....

 

[shotgun]

I am selling a set of SSM bars to do the conversion.
Since your kinda close,give me a call @ 215-740-2691.

 

[85 Cutlass Brougham]

It is also important to note that there are several 10 bolts, not just the 7.5 and 8.5. Be sure you are not getting the 8.2 10 bolt as it is not the same as a 8.5 but saw use in the GTO. There were a number of weak 10 bolts used in non-Chevelle A body performance variants. The only 10 bolt worth the trouble, in my opinion, is the 8.5. It became sort of a universal axle in RWD applications after the death of the Chevy 12 bolt and early Chevy 10 bolt. It was even standard on straight six Novas and Camaros. I don't remember for sure, but I think the 8.5 was not yet available in 1972. Also, there are 2 different axle widths for early A bodies. You have the second generation one which is 1968-72. 1964-67 used a different width housing. I think the newer one is the narrower unit. This is all off the top of my head, so you will want to research this before you spend your money on something which will not benefit you. I have been there and it hurts.

 

[joe_padavano]

It is also important to note that there are several 10 bolts, not just the 7.5 and 8.5...

Excellent advice. Also, while this shouldn't be an issue with a GTO, be wary of the "12-bolt" Type O axle. These were unique to Oldsmobile and were used under 67-70 Cutlii. While they have 12 bolts holding the cover, there are only 10 bolts holding the 8.5" ring gear. Parts are unique to this axle and difficult to come by. Most people advertise them as "12-bolt" axles, even though they are not.

 

[85 Cutlass Brougham]

Yeah, just remember when dealing with a 12 bolt that 12 bolt refers to the number of ring gear bolts and not to the inspection cover bolts. It is also important to note that there are 12 bolt rearends that are specific to 1/2 ton trucks and have nothing to do with passenger car axles. None of the BOP A bodies had very good axles as compared to their Chevrolet counterparts. I find it funny, in an *ss backwards GM corporate politics sort of way, that this was the case. Why not use the best rear axle in the pricier 442, GS or GTO as well? I dunno, but that's the way GM did things then and in some cases still do now.

GM did not build the best musclecars, just the most popular ones. There were far more interesting products and more daring drivetrains from Chrysler( 426 hemi, 413/426 Max Wedge) and Ford( Cammer 427, Boss 429, Boss 302) in the 60's and 70's, but GM generally had the better styling departments ( for the most part) and that's what sells the most cars. ( And GM was gun shy because of the Corvair fiasco that scared them off from technical experimentation) After all, most people buy image, not technical merit or there would be a lot more bland, reliable fuel efficient cars on the road today than there are SUV's that weigh 3-4 tons. Anyhow, I'll get off my soapbox!