| There are two distinct styles of factory rocker arm. The first used from 1968 to 1971 on the passenger cars engines is the cast iron non adjustable rail rocker arm. It is mounted on a bottle necked stud and is non adjustable from the factory. There are however kits to convert them to an adjustable format. |
| Rocker are comparison page |
| The second type of rocker arm is the stamped steel version. It was used from 1972 on up to the end of 460 production. It came in two versions: A non adjustable bolt down used on passenge car engines. The CJ and PI engines along with the early juice CJ's prior to 11-1969 were also adjustable. |
| The rail rocker arms have a tendency to chaafe the valve stems and can contact and unload the spring retainer at lifts above .525" so be carefull and look for contact. The stamped style is a bit better but still non adjustable. Crane offers a roller conversion kit for the 72 and newer rocker arms and it is a good idea if asjustablility isn't needed. The best conversion from a reliability standpoint is roller rockers with guideplates. |
