I have a 90 Camaro with the 3.08 rear. I was woundering if the 80's rear end would swap without much of a problem. The number is 22519735 N. B-04. I found it on craigslist so here is the link if you need it. http://siouxfalls.craigslist.org/pts/2618153576.html

 

Yes that is a rear for one of these cars.

It has provisions for the crappy Saginaw (cast-iron) disc brakes. You'd have to deal with all of that hassle, trying to get those to work. Not only just getting all the parts that aren't there, but also the different MC and PV that will be required.

As far as I know there's no such thing as 3.33 gears for this model of rear. Probably 3.23. The gears will have the ratio stamped on the edge; 42:13 would be 3.23. Gears virtually always have at least one of the pair whose tooth count is a prime number, and often both are. 3.73 for example is 41:11, both prime.

The posi looks like a stock Auburn unit.

All in all not my idea of the perfect rear end but if you need one real bad that would do until you could find a good one.

 

What he said^^^

It'll work but you still need brakes.

 

You'll actually be stepping backward slightly. Your 90 will have 28 spline axles. 82-89 will have smaller 26 spline axles.