Well, normally, theres a tag thats under a bolt on the cover. Those are usually gone in a couple of years. Then there is a number stanped on the housing itsself, it that has been welded over, we can still kinda get you in the ballpark.
All SmallBlock Camaro's had a 10 bolt rear. All the BB Camaros had the 12 Bolt. If it were a Z car, with a stout factory motor, it probably had a 12.
Any performance rear is not a open rear. Normal performance had limited slips, while the factory Hi-Horse cars had the detroit lockers, which was a option if you orders the monster motors. All the stock performance motors started having lower compression bot 73, by 75, the HP#'s started falling, bigtime! But, you could still order the 450 Horse 454, 425 horse 427, 375 horse 396....and have them dropped in. But you had to pay big time for a rear that would stand up to them.
Look in one of the 100's of rear end charts for camaro's, measure your width, face to face, then, measure your spring pad width, the big motored cars had bigger wider, bigger brake shoes also. With all those #'s, and look over your rear end good for stamped numbers on the machines surface by the rearend cover, you should find out which car it came in.
If its a 2.73 gears, open rear, its probably a normal, run of the mill, low compression 350 with a turbo 350.
As for the gearset, the axles only have to do with the carrier, the splines gotta match up. This would help if you were change out your carrier for a posi- unit. They'll be going by 10 bolt or 12 bolt, by your ring gear dia.
You can purchase a install-kit that comes with your seals, some shims, crush sleeve and new c-clips. When you change your gears, your gonna want to use new stuff anyway, or at least I would.
