What will these fit on? 12 bolt? or only 10 bolts? I have access to a set and want to put on my 67 Chevelle SS 12 bolt.

If the camaro has a 10-bolt, the brakes will fit 10 & 12-bolts. If it has the Borg/Warner 9-bolt, they won't fit (The B/W rear end uses bolt in axles instead of c-clips, usually found in Firebirds). They most likely are the cast iron calipers, unlike the 89-up which use aluminum calipers which are the prefered ones. The cast iron ones are not terrible, as long as the parking brake mechanisms are working.

Thanks for the response. My pop was going to throw them out and I was just trying to put 2 and 2 together. These disc came from a 88 Z28 with c clips.