I have a '91 RS with the 2.73 non-posi rear. Now what I'd like to be able to do is just swap the entire rear, with a posi rear that has 3.73 or 3.42 gears. I've read a post on here saying to just forget the idea of swapping the whole rear. WHY? Or is it actually ok to do(from a non f-body vehicle)? So I guess what I'm basically asking is what other vehicles share the same rear as thirdgen f-bodies?

 

None.

Many other vehicels use the same model of rear end, but these cars are the only ones with the torque arm mount. So no other vehicle's housing is compatible with the car.

4th gen ones will work but are longer, so 3rd gen wheels will stick out too far. However, a 4th gen rear with 4th gen wheels will fit a 3rd gen properly.

Probably the cheapest way to get posi and better gears into your car would be to find a junk one from a 6-cyl/5-spd 90-92 car, which will have 3.42 gears; and put the SLP posi in it.

 

that sux eh. Ok, thx for the heads up RB83L69

 

Also, the 85-89 2.8 v6's with automatics got the 3.42/open/drum rear. If you stumble across an 85 4-cylinder f-body with a manual trans, it's got a 3.73/open/drum axle! The 84-85 Camaro HO also comes with a 3.73/open/drum axle.

 

right on, thx for the heads up guys. See what I can find now

 

Problem with the 89-back rears (such as my 83 HO car) is that they have 26-spline axles. The $99 posi won't work unless you buy axles. And the cheapest way to get axles is - you guessed it - to buy a 90-92 rear. The price of buying a new 26-spine posi is greater than the sum of the $99 posi plus a 6-cyl rear end at thre yard, and there's alot more 6-cyl rears than HO ones, and they're not as sought after except by those few people who know what they're doing.

Of course, the ultimate score would be one of those 4-cyl rears for next to nothing which would get you the 3.73s, and a 90-92 6-cyl rear which would give you the axles, and then get the SLP posi.

 

Keep in mind that S-10 trucks and Astro vans used a lot of 3.42 and 3.73 gears which will work too and the junkyards are full of 'em!

Eric