Posted in wrong forum at first, sorry for double's.

So I have done a bunch of research about my "12 bolt" type O and its a pain to get parts if I can even get them at all with the certain model I have. I am looking for a rear end that can bolt in to my car that has aftermarket parts readily available. I have a 67 cutlass 4dr sedan (A body). What rear end/s should I look into and beef up?

 

Well Just about any 1967-1972 A-body gm rear will fit your car. Exception is the 71 72 Cutlass and Skylark rear whuch is the 8.5 10 bolt - that will require a driveshaft shortening. BUT everything else is still direct bolt in.
List-
1967-1972 Skylark, GS, California, Cutlass, 442, F85, GTO, Lemans, Tempest, Grand Prix (69-72), Chevy Chevelle, El Camino, Malibu, Monte Carlo (70-72)
So you can see there are plenty of cars to get the rears from.

12 BOLT CHEVY, 10 BOLT CHEVY, BUICK 8.2, PONTIAC 8.2, 12 BOLT OLDS 8.4/8.5, CORP 10 BOLT 8.5gm - THESE ARE ALL THE DIFFERENT REARS THAT ARE OUT THERE TO HOP UP.

10 BOLT 8.5 CAN BE BEEFED UP PRETTY QUICKLY - 12 BOLT CHEVY IS A FAVORITE OF THE CHEVY GUYS...EXPENSIVE HOUSING THOUGH.
FOR THE STREET ANYONE OF THERE REARS CAN PERFORM QUITE WELL.

12 BOLT OLDS IS REALLY NOT THAT BAD TO FIND PARTS FOR. IT IS JUST BECAUSE MOTIVE BOUGHT OUT RICHMOND GEAR WHICH STOPPED THE PRODUCTION...FOR A BIT HOPEFULLY... WE HAVE POSI UNITS READILY AVAILABLE REBUILD KITS AXLES ETC.

Jim- JD
sorry about the caps....

 

Monzaz, Why do you leave out 64-66 rears?

 

Because the 67 Type O axle uses the same lower spring mounts and same width as the 68-72 axles. The 64-66 axles use the flat lower spring mounts with a retaining bolt and are narrower. FYI, the 67 and 68 Type O axle housings have the same part number.

 

But aren't the springs the same? The 64-66 springs bolt on to the pad but thats the only difference I can remember other than width. I know back when I was parting out and piecing together a lot of Chevelles I could use mix and match any year.

 

Nope. The 64-66 springs use a full size coil at the bottom. The 67-72 springs use a reduced diameter coil at the bottom that fits over the pilot built into the lower spring mount.

 

OK Joe I must have been keeping the spring with each style axle. Its been 11 years since I was doing for a living on EBAY. I forgot some since then.