What rockers are you using with Edelbrock RPM heads?I do have roller tip rockers.Can they go bad?I have knocking on the right side when i let go of the gas.Left side is OK.I adjusted valves two times and no luck.
What do you think about Crane rackers 11801-16?
I assume by "knocking" you mean valvetrain noise? My first supicions would be a broken valvespring, bent pushrod, or a flat or near flat cam lobe. Spin the motor over with the valve covers off and see if all the rockers seem to be moving about the same amount.
"This is not a cheerocracy...I make the cheercisions around here"