Ok the 901 Comp springs is what I have, so they should be ok. Now I understand the the clearence for the valve guide to retainer, make sure the retainer doesnt hit the top of the valve guide at full lift, correct. But what is the rotator? I just disasembled the heads and there were the standard spring, retainer and locks and under the spring was a washer, I'm guessing its a shim to get the springs to specs with the cam he was using. So what it the rotator and where is it located, sorry for the ignorance!!!

Butch