Hey i have a 87 firebird 305 carb with auto tranny, thought to be 2.73's with limmited slip


I was wondering what rearends besides 3rd and fourth gen cars will fit? Mabye some s10 or old 4x4 truck with lower gears and posi? Anyone know what other vehicles have same size?

 

Basically limited to 3rd and 4th gens due to the Torque Arm being required. 4th gens are a little wider than a 3rd gen.

That being said you have 9 bolts, 10 bolts, and Dana 44 (good luck) that came in the cars.

 

As always, "limited slip" IS THE SAME THING AS "posi". "Posi" was merely GM's trade name for "limited slip" at one time, and the name stuck.

So if you have limited slip, you already have posi.

However, you probably don't. Those base-model LG4 cars were rarely ordered that way. Although it's always possible that somebody has already put a limited slip carrier in it before you got it. More likely, you have what we would ordinarily call an "open" differential, with UNlimited slip.

No other chassis has a rear that will fit these cars. Gotta be a 82-02 F-body. 93-02 rears are longer and will make the wheels stick out funny and look poseur, especially if they're the stock pizza cutter wheels, either the 15s or the 16s, that came on these cars. However the combo of 93-02 rear and 93-02 wheels fits the same as the combo of 82-92 rears/wheels, because the wheel backspacing difference exactly offsets the axle length difference.

 

Really not any other truck or car have the same dimensions? Not looking for a proffesinal build, just a fun cheap red neck ride

 

It isn't so much the dimensions (width), as it is the suspension type. No other car or truck came with 2 trailing arms, a panhard bar and (the biggest issue) the torque arm. Some had those types, but not the same lengths or positions.

So no...No others will be a swap. Unless you are ready to do some serious cutting & welding.

 

Brackets can swap over easy enough with some cutting and welding. The biggest issue is the torque arm, like stated earlier. It's cast into the pumpkin design itself. There is no bracket to cut and swap for that one. You'd have to make your own. By the time you do all that it'd be far easier just to grab a good used one from a yard for $200.