Uppers or lowers?? The lowers should be the same as in the uppers. The lowers would be different I guess as in the bracket that holds the parking brake cable.
Tombird68, I took my old replaced splitting mount to compare with my '68. I sure don't see any difference between it and either the left or right side.
Have to find my old ones to figure out why cause remember they where very simular look'n. May be an angle or hieght difference for the shocks. Or could be so they clear the axle or springs. My 72 GM Pontiac parts catalog does list different #'s for left and right.