I am ready to upgrade my '89 Firebird's rear-end to a used Torsen unit out of a 4th gen, but I knew I had to upgrade to 28 spline axle shafts.

No problem, I have a wrecked '92 Camaro RS (305, T5) for parts. So I take them out and count the splines, AND THEY ONLY HAD 26 SPLINES. WHAT THE HELL?!

The point of this post is that the factory doesn't always do what they say they will, so don't assume that a '90-up rearend has 28 spline axles. You gotta count them.

 

I've been around thirdgen's a long time, but I've never encountered/heard of the issue you describe (GM's wild and crazy though so who knows?) Would it be more likely that the 26-spline axles, etc. were swapped in at an early point for some unknown reason?

JamesC

 

Yup.

Mass production being what it is though, the odds of that car HAVING COME WITH those obsolete parts, are somewhere between Slim and None, and Slim is now sitting in None's lap on the bench. More likely, somebody just swapped out the whole rear at some point in the car's life.

In case anybody ever wonders why I tell people to IGNORE THE "CODES" and instead LOOK AT THE PARTS, or thinks I'm some kind of a jerk for telling them that the "codes" ARE NOT RELIABLE, this is exactly why. Stuff is just way too easy to swap around.

Go here. http://www.summitracing.com/parts/SAG-EV10-4/

 

I don't mean to bring up an old thread, but I just got back from a salvage yard and found ANOTHER '92 Camaro RS with 26 spline axle shafts.
This makes three '92 Camaros with 26 spline axles so far (I found another one a few months back but didn't say anything).
I guess they could have been swapped at some time in the past, but three of them, all the same year? I think it's looking more likely that GM was trying to get rid of all their third-gen inventory in anticipation of the wider 4th gen axles, so they just started throwing some left-over 26 spline alxes on the assembly line.

 

you would think and left over 26 spline stuff should have been used up long before 92, but who knows.

 

One would be rare. Finding 3 like that really makes you start to wonder.