I seen the same thing with valve lash loops at the track. Minimal if any on the small block with a solid roller at .700" using a T&D rocker which Pittsburghracer now owns. With a victor head and 1.6 Harland Sharps just bolted on with lash and as the engine would run gave me these patterns. Not perfect, but doesn't look bad and just had the guides checked and giving an outstanding A+ no wear from Sanchez. So their not hurting anything anyway. I haven't done any measuring except for piston to valve clearance.