Well, it's the stock rocker arm assy. I may need to do more research on lifter preload. I just can't fully explain the noise going away after the engine come to temp.
As the engine gets to temperature the push rod and valve stem will grow in length and physically get longer, I'm guessing .004"-.010" but I've never measured it, and this will take up any slight clearance between the valve stem and rocker arm. The actual amount of growth is based on temperature and material (thermo growth of aluminum and steel are different) and this is why there is a cold clearance between the rocker arms and valve stems of engines with solid lifters. :evil2: