I just bought a 12 bolt rear end for my 70 Camaro at a swap meet. The code on it was COS0115G1. Anyway i was not sure it was fo a 70 until i measured the axle housing. I paid $900 for it. All the gears, bearings, wheel cylinders, drums, shoes, springs, posi clutches, and springs have been replaced with new. The rear end was also bead blasted and painted black. The guy said it was originally a non-posi unit and had 3.08 gears in it. He put in a rebuilt posi carier and new 3.73 gears. The rear end has not even been ran since the new parts were put in. Still has yellow gear marking compound to check the mesh. The parts alone cost almost as much as i paid for it,so i think i got a good deal. The only reason i put it in here is because i want to know what kind of car it came out of SS or Z28? I am leaning towards SS because of the gear ratio, but was it a 350 or 396 that it came out of?

The COS code says it was a 3.07 non-posi 12 bolt used in 1970 only. (10 bolt were 3.08).

That was the standard rearend used in SS350 with TH350 auto tranny, so most likely that is what it comes from. I suppose the 3.07 could have been ordered with SS396 too, but their standard ratio was 3.31 whether they were manual or auto.

Thanks for the help. http://www.nastyz28.com/ubb/smile.gif