Some years ago, I can't remember how many, I resurfaced my rockers because they at up two feeler gauges every time I adjusted the valves. I used the HRL "offhand" method of grinding on my belt/disc sander. I have also done that to "cone/radius" valve lifters, per Bruce Crower. Anyway, 50,000 or so miles later there is no appreciable wear on the rockers. So, they must be made of some hard stuff. I'm using stainless valves and bronze guides.
On my "breathed upon" Norton motorcycles I have used lash caps as the only way to keep the ball-shaped rocker end from digging a hole in the valve stem. Easy to change lash caps, big deal to resurface valve stems. But the extra weight does cut the top RPM by a couple hundred. Not a problem on my 235.
