Stainless, Bushed PRW Rocker Arms
Sorry for the rapid fire questions…not expecting answers back, just food for thought.
How much preload do you run? Do you check it/adjust it often? Do you ever get valve toss when you get on it hard? Have you run an oil pump prime with the valve covers off to make sure you’re getting oil in the shafts? Maybe the feed hole from the cam is choked down or blocked. Also check hole direction as others have mentioned.With the issue seemingly isolated to specific cylinders, have you checked those particular valves and guides? Maybe something is off, like they’re sunk a little deeper or shallow than others so their geometry is a little different…not all machine shops equalize the heights, or the guides are a little tight and have to get “run in”. Bolting on heads out of the box without set up from a machine shop can have some of those issues.
I run these rockers too, but really only at the strip, and with a solid flat. Wondering if too much preload was keeping the roller in the same spot vs with lash where it unloads and spins with every cycle.
I think it’s pretty awesome you put so many miles on it. Could just be crappy materials that were meant for the average classic that only goes out on nice weekends. All the best to you on your quest!