If it's a round hole, I found when the shim is bent to the stands diameter, the hole becomes oval, and will pass oil freely to the shaft, at least when I use them, they do.
That'd be a pretty severe oil leak at 60#s constant pressure.
That's why I posted the link, the rocker shafts only get oil a "spurt" at a time, when the cam/bearing holes line up every 2nd crank revolution.
