[Mr70]

I think originally they used Part #3894475,used on 1967-68 Camaros & Chevelles w/Frt.Disc brakes,and 1968 Novas w/Frt.Disc brakes.
1967 Camaros w/o Frt. Disc used a different knuckle,part #3902952.
1969 Z/28's also used a different knuckle that went by part #3966151.
In the early 1970's,they discontinued the 475 knuckle and merged the same earlier Frt. Disc brake vehicles with the 151,so that one will work on your car,if you don't want to be assembly line correct.