Good_Music_n_Cars

hello everyone, i have a 71 cutlass and i want to put rear discs brakes on it. first i want to get a posi rear end, so i guess my question is this? what rear ends will fit on a 71 cutlass and what is the process of putting rear discs on the rear end. thank you much ! -Lee

joe_padavano

Any 68-72 GM A-body rear axle will bolt in, however there may be up to an inch difference in the driveshaft length, depending on the axle type. Chevy 12 bolt axles are the strongest, and priced accordingly. You can also now get custom housings to fit the A-body, including a Ford 9". The disc brake choice will depend on the axle you pick. It's possible to cobble parts together from an F-body and Toronado, but if you don't know what you're doing, you should stick to a kit. Note that you'll need to change the master cylinder as well.

monzaz

I would keep that rear and make it posi . It is a good strong diff. If it is a true 1971 rear it will be a 8.5. , which means you can use any 8.5 posi unit from any 70's car including camaro, regal, trans am ,monte carlo, impala (10 bolt 8.5 rear), grand prix all 1973 -1977 car came with them. OR... you can do a 30 spline axles from Moser conversion and a 30 spline unit from a 1990 -1996 rwd car will work too . the 8.5 has huge aftermarket support posis bearing kits gears you name it.

If you close I will help you or build it . We have the Buick guy up grade there 8.5 71 72 rear all the time Moser 30 spline axles and Eaton 30 spline hd units and or spool. I will put them against any 12 bolt rear . Think twice before unloading that rear. Ok? Good luck on your choice.

1" on the drive shaft is good info the 8.5 rears have a longer pinion then any a-body car in the 1965-1972 muscle car era.

List of cars to get a rear from direct bolt in 1965- 1972
Chevelle
Monte Carlo
Elcamino
Gto
Tempest
Lemans
Skylark
Grand prix

Good_Music_n_Cars

thank you two very much for the information. you guys narrowed it done perfect. and after reading so many different things, it's good to get a straight answer ! i will let you know what i decide in the next couple weeks ! -peace - Lee