[Jeff Lee]

I did not notice your lash settings previously. I can tell you from my own experiences with a "hydraulic" stock eliminator cam (which in effect is a solid cam, hydraulic by definition only, not in useage), that anything over .010" would beat up the valve train and not retain a consistant tolerance. If your lucky it just breaks rockers, if your not, you will probably break Schubeck lifters. My opinion after breaking several sets of Schubecks is it is a harmonic problem. Remember, they glue a ceramic type structre onto a steel lifter body. But I have no way to prove it as I do not have a spintron to scientifically verify it. And I've been down the complete path from low to high spring pressures and from a single spring to spring with dampner. I can tell you that the absolute best control I had on my valve train (using billet cam as well, with no dips for lifter pump-up; a true solid cam) was keeping a "tight" .0025" - .003" lash with pushrod cup at it's maximum height. And mine ran faster with tight lash vs. loose lash. I see no reason that would not hold true for your engine.
I would also suggest you adjust all valves rotating the engine with a wrench, not a starter.