use rocker can be trouble a customer of mine pickup a set of used rocker for a smoking deal and they were junk .sent them in to get rebuilt . the same price to get new .jonhy is rigth try to keep a way from used roller rocker and roller lifter and springs if you are driving this a lot put a new set stock ones on it i hear the rocker needle bearings go bad at 30.000here is a list of the ones i like scorpions howards - crane lunati and crower ss the miller look good with the mid lift precision geometry but i have not try a set but geometry on rockers is a big deal to me