My 88 Camaro Sport coupe seems to have the factory rear end in the car, so I believe it to be a 2.73 rear. But it seems to have a posi. Was this a possible option? If so does anybody have the rpo code for this?

 

Yes it is possible.

No it is not likely. In fact, very very UNlikely, that the car would have come that way.

It is also possible that somebody got a posi carrier out of a performance car, and put it in that one; since alot of 350/auto cars would have come with that gear and posi. So your RPO sheet wouldn't reflect that.

RPO for posi is G80. I don't know the RPOs for the various gears.

"Seems to have posi" happens about 3 times more often than actual HAS posi. Have you changed the fluid lately? I suspected not.... so that's a great excuse right there to take off the cover and look. Which is of course the only way to be sure of WHAT'S IN THERE NOW, regardless of what's "possible" from the factory, or even what can be determined that definitely came in it. And of course the same applies to the gears. One true look, and all the guessing and "seems to" is over with. You know for sure.

 

The makeshift 10-bolt going into my car soon is a factory 2.73 Posi from a '91 Z28, for what its worth.

 

Thanks for the help. The rearend is getting tossed out for my 85 iroc rearend anyway.

 

Check whats in the new rear end first... you might end up with the same thing, or something not much better - not enough to make the rear end swap worth it anyway - like a 3.08, or an open diff, or something.

 

Right:

Rule #1 of determining what's in a rear end (posi? or gears):

The ONLY way of being sure what you've got / are getting is

Rule #2:

In case you think you have some other way that will work, see rule #1.