My current set up is the stock 2.73 non posi on a '89 v8. I can get a posi carrier from an '86 iroc from a local junk yard. Will it bolt right on? Also can I use the ring and pinion from a '91 v6 since it has a higher gear ratio?

 

the carrier will bolt in without a problem. I am pretty sure the axles were the same spline throughout the production run. make sure you get the 10 bolt rear though. There are a few 9 bolt units out there and they look exactly the same but are very different.

http://www.chevyhiperformance.com/techarticles/49998/
contact mark@hpsalvage and he can give a pretty good deal on a low mileage rear assembly that will be guaranteed to work.

I am 99% sure that the rear end from a 93-97 camaro will work also. The only concern I have are the splines.

 

I think your going to have a big problem here.

In the late 80s (88 up i believe) GM changed from a 26 to 28 spline axles. and you also had 10 and 9 bolt rears in these cars too. none of these parts are interchangable.

You could swap in the entire rear end though, that should be a breeze.

 

regardless of what you might read on here the number of splines on the axle will have zero effect on the ring and pinion set. you can use any ring and pinion set as long as it's for a 7.5/7.62 ten bolt and the carrier series matches the gear set.

 

Yes gears will be fine but the posi carrier isnt going to work.

 

Hey 1981LT1, thanks for the link, lots of good info.

So the posi carrier from the '86 Iroc might not work because it's designed differently? If anything I can buy all the guts including the pinion yoke. Will that work?

Any other thoughts, let me know.

 

there's about a 10% chance the 89 carrier will have 28 splines. take yuor axle and check it before you buy it, or buy the carrier and the axles too. axle spline count is a simple problem that is easy to over come. don't get hung up on that minor point.