69 340 having oiing issues

What up out there? I was hoping that someone could give me an easy answer for my 340 Dart, a few weeks ago she start a lifter tap, this engine had been sitting since 1988 before I brought it home to start fixing it up about a year and a half ago, first thing I did was pull intake manifold, valve covers, oil pan, timing cover. All looked real good, cleaned everything up, replaced badly caroded timing cover, re-gasketed everything,put gas in and started, sounded good ran pretty good around block, moved round body shop all last summer, but a month or so ago I started driving it a lot more and it started tapping so pulled valve covers to adjust and at least 2 pushrods [273 adj. rockers and cupped push rods] had been beaten to death on the cupped end. Now these have been on this engine since the middle 80s with never any problems[at first I thought it wiped a lobe]. So ordered new Mopar purple cam and lifters, new adjustment bolts, and new 7.237 inch long pushrods. Installed cam, lifters, push rods, and the new adjusting bolts, ran everything with high zinc break in oil and cam break in lube poured on cam. After running for 20 minutes or so I shut it down, there was no smoke, as in very little oil to rocker arm shafts if any? So pulled dizzy out and pulled off rocker shafts and got out my pre-lube tool,spun oil pump, had 45 psi at gauge no oil coming up pedestals? WTF? how could that happen? The next night after reading everything I could find. Went back out and started trying to rod out oil passage with .030 mig wire, was the only thing I could find to go beyond the head section of oil passage, a little while later after removing plugs and cranking over a bit some oil started coming up through both pedestals. Ran engine again still not much oil to shafts and rocker any thoughts or advise ?