upper end oiling question

I'm helping a friend with his engine (roller 408), and he is hearing a slight valvetrain noise. Now he had his engine rebuilt at a performance shop with a decent reputation, however the more we look at it, the less we think of the reputation. On breaking it in we were a little disapointed in the oil pressure, 25 psi at 3000 rpm, upon inspection found that they used pushrod oiling, as well as shaft oiling. He then put solid pushrods in and had the lifter bores sleeved. Now with the high pressure pump we were looking at over a hundred. Next went back to stock pressure pump, everything seemed fine 527 HP at 6000 rpm, drives great.... but. There just doesn't seem like enough oil is getting to the rocker shaft, which is a Harland sharp setup. We ran the engine with the valve cover off , actually cut up a valve cover not to make a mess, didn't need it, oil only seemed to drool out of the rocker shaft, under the rockers. Now I've run stock chevy engines with the valve covers off and there is plenty of oil going everywhere, not on this 408. The oil feed seems clear. Are these like this with poor oiling to the upper end? Or do we still have some sort of issue here. I'm planning on building an engine very much like this for my Barracuda and want to avoid issues such as this, and help a friend. Thanks!