Looks to me like 11 by 2 drum Bendix hardware is basically the same from 51 thru 70 1/2 ton trucks. Exception would be self adjusters used around 63. Even this self adjusting hardware works fine on earlier years. Lots of the same stuff around on other sedans and trucks with Bendix 11 by 2 brakes. It is all the same. I have even used the brake hardware from a 67 1/2 ton chevy on the front of a 49 1/2 ton F***. (Respectfully referred to as a Chevy F1.)