Desperation
To top it all off I've had lifter noise issues from day one, with racer brown cam and 1.5/1.6 adjustable rockers I've tried 2 sets of lifters and on my second cam with the same result. Lifter noise that will fade in and out with rpm.
Are you getting oil to the top of your motor? Could be pluged oil passage from the cam bearing to the top of your block, cam bearings not installed right. Pull the dist and rocker shaft off one or both sides, use a oil pump primer while slowly rotating the crank to line up the oil hole in the camshaft with the passage leading to the top of your motor to varify oil getting to the top. Since your on your second set of lifters and second cam, I think you can eliminate the bad parts theory.