In the middle of a cam swap. Took off the rockers and noticed the tips of the valves where the rocker arms push down on the valves on are worn. Looks like very slight grooves or indentions. The stock rockers look fine. (stock valves btw) I have PRC Dual springs with about 3000 miles on them. Are they too much spring for the sock valves? 3 cams have been swapped out since. First and biggest lift cam was an MS3 before going turbo. I'm running cams in the .550 lift range since. I never notice this before or maybe never have paid attention. Anybody ever encouner something like this? I'll post pics if I can find my damn camera.

 

Check your wipe pattern. Someone just ran into a problem with extreme wear on a set of aftermarket heads, turned out the installer didn't check the wipe pattern and the rockers were pushing on the edge of the valve stem. Eventually wore right through the hardening on the valve. Those springs shouldn't be the issue, but your valve train geometry is likely the culprit.