Well I looked at the site posted above. I looked at the rear end some more and you can see evidence of the factory traction bar. About 4 of teeth are chipped that's real bummer. I turned the pinion and it turns over easily. From what I can tell the pinion doesn't have any damage to the teeth. The rear end doesn't look like it's ever been apart. There weren't any of the broken off teeth or parts inside the housing. I wouldn't put the gear in a daily driver for sure. A trailered restoration that only drives in and out a trailer at shows could go a long time with this gear.
This is what I think this rear end is.
QC - 12 Bolt 4.88 gear standard brakes
03 - March
21- 21 March build date
2 Shift code
K176
K - Nov
A - 17th
6 - 1966
So what this rear end is:
1967 Camaro 12 with factory installed 4.88 gears, standard brakes, built on 21 March 1967 on the 2nd shift. The housing was cast on 17 Nov 1966. ???? Something tells me this isn't a 6 cylinder 3 on the tree Camaro rear end.
http://www.camaros.org/radiusrod.shtml