swapping out ring and pinion 7 1/4

MTSC says in '63 a spreader was needed, and the 7-1/4" was still a shims-type unit in '69. The '72 FPC shows the use of a spreader for disassembly, but the '72 FPC has a little box on page 3-1 (exploded view of 7-1/4" rear axle) captioned "1972 LATE TYPE" which shows an adjustor, lock pawl, and bolt. The '73 FPC shows only the type with the adjustor, lock pawl, and bolt, so there it is.