There are two different SR20 Rocker arms. One on right is roller rocker arm, the other one is solid rocker arm. Roller ones are suppose to be smoother, but if you over rev the motor, that thing is going to give you problems. I think this is one of the main reason B15 redline had to go lower. JDM SR20DE made after September 1995 came with roller rocker arms. But people are swapping back to solid rocker arms for more rpm and reliability.shaolin_racer said:one more question, what is a roller rocker? im guessing it has to do with the valve train.