Hey guys I have a 82 firebird with a 350. Was originally a v6. I looked under and it's a 10 bolt cover on it, anyone know what kinda rear end im working with? Also, what rear end should I replace it with that would bolt right up. Also, if it matters I'm running a 700r4 tranny

 

No, you'll have to jerk the cover and take a peek. More on that in the 10-Bolt FAQ sticky.

Any 82-92, 9- or 10-bolt is a direct bolt-in. There are, of course, some after market pieces.

JamesC

 

If it's the original rear end then you have the 7.5 GM 10 bolt with 26 spline axles. Only '82 to '92 Camaro and Firebird rear ends are a direct fit, and '93 to '02 Camaro and Firebird rear ends will bolt in, but they are about 4 inches wider. NO other rear ends will fit.

 

No other junkyard rear ends will fit however there are a few aftermarket options. There are direct bolt in 12 bolt, Dana 60 or Ford 9" diffs that can be installed. Expect to pay anywhere fro $1000 to over $2500 depending on which diff you choose or what options you buy them with.

The problem with third gens is that they use a torque arm suspension. With the torque arm bolted to the diff, there is no easy or inexpensive way to upgrade a junkyard diff to use the torque arm.

Is a better aftermarket upgrade expensive? Yes. Is it worth it? Drive yours hard until you break it then decide. You can spend money to beef up your 10 bolt but in the end it will still be a diff with a tiny ring and pinion that can easily break.