Meant to add that the Chapman heads use 11/32 stem BbC length 2.25" valves that seem way lighter than a comparable BBM 2.14 or 2.18, also I'm running Ti retainers and spent a lot of time on setting up the ideal rocker sweep and lateral clearances, I think that helps a little bit too.

Also it's a b motor so the pushrods are comparably lighter and stiffer too, I think it all adds up, not to take anything away from
the bullet lobes.

Back in the mid 90's I crewed with a couple of guys in the early days of Pro 5.0 and way back then Bullet was cranking out all kinds of HR grinds for us to try, I think they saw the potential before most other cam mfgs did