The hughes rocker has no pushrod clearance due to centering the roller with stock rocker stand locations. The mancini rockers have pushrod clearance but the roller is off center to the outside making them seem effectively "longer", that is why they fit trickflow heads so well since they have relocated rocker stands. The reason the guy from mancini has never heard of this before is because most guys just run shitty geometry and don't know any better. My advice to anyone not putting together a "custom" engine is put 273 rockers on and be done with it, otherwise do the research, figure out the compromise and call Mike at B3. I do agree Dave can be an *** but it's his business and he can run it the way he wants, doesn't mean he's right or a nice guy but the beauty is you can choose not to buy from him. Speaking for myself if I cut off everybody in the hobby who has pissed me off I would have very limited options to do business with lol.