update: I ended up cutting a vent groove in all of the push rod seats of the lifters, bench bled lifters, re assembled, set valves @ 1 1/2 turns past no slop at TDC, and went for a ride. it ran very well, smooth and quiet at top speeds. so as it turns out, there was indeed, air trapped inside of a lifter that couldn't work its way out and was causing the loud clacking noise at higher rpm's and occasionally at lower rpm's. I have to give a big shout out to Dave's blog and his direct advice for helping me solve this issue. priceless info here on the "bolt"
