how much clearance is needed between the rocker and the retainer? is there a safe minimum? mine look very close near the edge of the retainer but are not touching. i'm scared that they might hit each other at 6k+RPM.

 

Minumum of .020" clearance throughout the travel of the rocker arm.

 

I like to see a minimum of .060". In case of float, I question whether .020" will be enuf.