Up to '76 for the yoke. Axle shafts will depend on what you want to do lug bolt pattern wise. 6 lug can be done using up to '70 as a direct drop in, '71 and later can be used to change to 5 lug (with the appropriate drums), but the axle shafts are about an inch longer, so some alteration would be necessary. A machine shop can shorten and regroove the later axles to fit your early housing. Axle shafts from the '77-'87 10 bolt will work, too.
