None of my 500s seem to have valve rotators; anyone know what year Cad started using them? If 77-79 425, can the setup be transferred over to the 70-76 engines? thanks, Bruce Roe CLC # 14630

Bruce, Our Olds 455 boat engine conversions (70 - 75 blocks) were originally equipped with valve rotators. When we do rebuilds and head/lifter/cam changes we leave the rotators out and go to standard retainers. With hardened valve seats and decent roller tip rockers the rotators aren't necessary - more trouble than they're worth, and they add a significant amount of moving mass to the valve/spring assembly.

Provided your guides, stems, locks, rockers and retainers are in good condition, with no set wear ( a wear-in spot that starts a groove ) the valves should rotate or dance while in operation. You can witness this if you set your timing using a timing light with the valve covers off.