I'm running factory adjustable arms on heavy duty shafts with the stud kit and the aluminum spacers and shaft supports from Precision
Oil Pumps. I'm running .540/.565 lift on a hydraulic flat tappet cam, 320 lbs. open spring pressure, and hardened 7/16 pushrods. No problems whatsoever. I went with the adjustable rocker arms in case I wanted to switch to a solid lifter cam later, so I don't know how well the non-adjustable rocker arms work with the edelbrock heads. And take Anthony's advice and open up the pushrod tubes in the intake. I did a test fit with my intake and pushrods and everything in place, and had 3 pushrods rubbing on the intake. Opened up the pushrod tubes a little and all was well.