COPO

[tmodel66]

COPO was also used to get a Camaro built with a non-standard (non-RPO) option.
An example is in 1968 4:56 rear gear was a RPO G82 in 1969 you had to get 4:56 gears using COPO 9511

I find this last statement about '69 very interesting. I took my rearend apart to rebuild it and found 456 gears in it. They are GM gears stamped  6/69 and my car was built first week of July. My POP says my gears should be 331. The car is a L48. Could these be COPO gears or what happened?

[tom]

If it was ordered that way, the POP should show it. Possibly someone swapped an axle. Check the axle code on the front of the passenger side tube. I know I swapped a couple of boneyard axles back in the day. Fast cheap way to get a posi, or to fix a blown rear.

[JoeC]

Some gears were dealer installed. I had a 1970 SS396 Nova with original dealer new car paperwork showing they installed 4:10 gears

[KurtS]

IIRC, Nova's had very limited gear choices. Hence the dealer install.

[tmodel66]

It's a numbers matching car so the rear end is the correct one for the car. I guess I'll have to go with dealer install. The only original paper work I have is the POP and owner's manual.