So I am receiving some conflicting input on my engine build. On one hand I was told to throw away the rotators on the springs and so I bought a new set springs with non rotating keepers. But when I picked up my heads from my machinist (3998993 Now with 2.02 and 1.64, decked with rod guides, screw in rocker studs, bowl cut and hardened valve seats) And he had put a set of rotators back on the heads and told me that being a street motor I needed them. Anyone have opinions or input on this?

 

You don't absolutely need them just becuase it's a street driven engine. Almost none of my engines use them and you'll never see them on aftermarket heads.

For stock and mild performance builds they are OK. I've reused them myself if the springs are mild (like Comp 981s or similar) and the engine isn't going to ever see the high side of 6000.

Note that becuase they are thicker than a non-rotator retainer swapping them out will require rechecking your valve spring installed height. On most factory cast iron heads the spring pockets on the exhaust side are machined deeper by about 1/16" to compensate for the extra thickness of the rotator-retainer. Switching to non-rotator retainers means you need to drop a .060" shim in each of the exhaust pockets to get spring installed height back close to stock spec (1.70").

 

By high side of 6000 do you mean like 6500+? Or 6800+? Would I be able to stack two .030" shims in there? My cam is specked to 6500 RPM