Did you buy these heads new and install them yourself? Just wondering if they had the springs swapped out or are dead, if they were used. I assumed they had the factory installed springs and were somewhat new... which would be more than good for the cam you're running.
Ever try that vacuum gauge to see how it reads?
9psi at wot... that is at the carb while running at the lake... not on the trailer?
Again... checked out the parts in the dizzy and wire going to it?
Dude... running out of external likely things.