Maybe this will help. These are 68-70 (pair) there are two versions of the drivers side, early and late. Both versions share the same casting numbers but the early versions have the casting numbers cast in the typical protruding fashion, later versions where the casting number was debossed (looks pressed into the cast iron surface, not protruding). The later versions started showing up sometime during the 1970 model year. The pair shown here are early versions