i have a 90 camaro rs <now a lt1 car> and the rear is 2.73's ive located 2 rears. first is local. its a 4thgen rear. <disc rear> 323 posi. complete 200 dollars.
other is in florida <im in virginia> its a 3rd gen 323 posi rear175 dollars. being both are complete. the florida id have to have shipped. what would you guys do? and is a 273 to a 323 much of a power increase?

 

ive been told that 4th gen rears bolt under 3rd gens just fine


i plan on getting a 4th gen rear for my 82 eventually, due to them having better posi units than the older axles

 

THE FOURTH GEN REAR WILL BOLT UNDER THE 3RD GEN BUT IS WIDER WHICH COULD LEAD TO HAVING TO BUY NEW RIMS PLUS EBRAKE CABLES AND SUCH I DONT BELIEVE ARE AN EXACT MATCH. NOT SAYING IT CAN'T BE DONE BY ANY MEANS JUST A LOT OF HIDDEN COSTS

 

Hey I found this on a website http://www.skulte.com/adapterfaq.html
Using a 4th Gen Rear
If you've changed your third-gen rear to a 4th gen rear, you do not need adapters. The 4th gen rear is approximately 2" wider per side. This is the same as using a set of 2" bolt on adapters.

You could run 4th gen wheels or aftermarket ones designed for the 4th gen without any problem.A lot of people who want to run 4th gen or zr1 wheels on their 3rd gen go with a 4th gen rear so they don't have to use spacers.

 

Personally, I'd go for the thirdgen rear (the wider fourthgen rear does't appeal to me). The 2.73 is a road gear, the 3.23 devoted to a bit more performance. The seat-of-the-pants dyno will tell you all you need to know, especially with an LT1.

JamesC

 

4th gen rears are common as dirt, and there's no point in getting one unless you're actually planning on running 4th gen or corvette wheels. If you're sticking with stock rims or any other rims with the same backspacing as stock, what's the point in a 4th gen rear? Besides that, if the thirdgen rear you found is an 89-92 vintage w/ disc and posi, they're a lot harder to come by for a decent price than 4th gen rears. Also, regarding the difference in posi carriers, the 89-92 posi carriers are identical to the 93-97 ones (Auburn). The only 3rd gen posis you want to avoid are the earlier Eaton Gov-Locs. The 89-92 rears also have far better rear discs than the 82-88 ones. The 4th gen posis that are a big improvement over any of the thirdgen units are the Zexel-Torsens found in the 98-02 rears. Just my .02.