[mattfranklin]

1) Like a previous comment said, checking the push-rod length is a priority here.

2) The special retainer setup might change the geometry of how the rocker tip works on the top of the valve. Another thought was, do the stock rockers contact the retainers in any strange way through their range of motion? I didn't see any marks, so maybe not. Unless both the rockers and retainers have been changed since the PO had the problem.

3) I'm also wondering if these valves are new or if the PO beveled the tips to get rid of burrs and bad wear patterns. Clumsy hand beveling might explain that appearance. I've seen pros put on a bevel before grinding the valves, just to make sure the valve could be centered and straight in the grinder, but the bevel is normally minimal and very clean.