FYI Interesting thing that we use to get into on valve noise. Lets say that all the shafts,rocker arm, adjusters are perfect. We could set 7 valves at .004 and 1 valve at .006 and that one valve would sound like a hammer mill. Then set all 8 valves at .007 with very,very little noise.
Back in the 40 hp days ,the early "round boss" heads were supposed to set at .008 (cold) They closed up as the the engine warmed up. These engines ran pretty quite until they started burning exhaust valves. We got a shop memo that said to set the exhaust valves at .012 and intakes at .008. Talk about singing a tune and pretty soon the rocker studs stripped out of the heads. We installed the modifier (factory) kit and the adjustment went back to .004 and ran very quite until they again started to burn exhaust valves. We then started setting the valves at .006 . No more burned valves and they ran very quite.
VW changed the head on the late 40 hp to the "square boss" 373 type head. The valve clearance open up as the engine warmed up. The rest is history.
I always set the valves on stock engines at .006
I have no problem on using the high price spread on the rockers,push rods, shafts, Its just money
I would make a bet that at least 70% of the Type-1 rocker arms out there running around are original and have a little wear issue :shock: