To adjust the rockers are the a torque to spec or do they adjust like a (dare I say it) Chevy lifter (tighten to quiet and add a 1/4 turn)? They are hydraulic lifters.
Turn in about 3/4 turn past zero lash, to get you started. I have read from 3/4 to full turn, but then you are always making a subjective call on hydraulics, what zero lash really is.
I prefer solids myself, but have a hydraulic in my Barracuda for the time being. Love the sound of the Thumpr, Comp Cam.