Those rockers are from RAS, Rocker Arm Specialists. I've heard that they went through several versions of those, trying to make them live. I had a set that used small engine 2 stroke rod bearings, caged needle bearing type, that were used in the roller wheel. On the dyno, my set lasted about 40 minutes before the needle bearings gave up and the rockers started coming apart. My opinion of them is that they are pretty, but essentially junk if you actually want a running engine.
