I went to do an oil change today. 331 low compression engine, AFR heads, probe pistons and probe rods and trick flow stage 2 cam. I race it and drive it every day to work. Racing I take it up to 6800 rpm.
It's not the rocker arms, here are my rocker arms. We didn't know either, took it to my engine builder and he knew right away.
I thought valve retainer at first but now I'm going with side of piston at rod ? How long before we find out ?