My old '66 Commando four speed had a 7-1/4. 10/19/65 SPD. After I broke the right axle and the previous owner had broken the other axle and two sets of spider gears I replaced it with a '67 3.23SG 8-3/4. The previous owner bought it in 1975 and I bought it in late 1980 (broke the axle in Oct. 1981).