I think a lot of people forget that a running motor never sees the valve held open very long like a flow bench measure flow at. As Andy said when you lift the valve open more the motor has the opportunity to suck in more air than it does at a lower valve lift for the same duration Now when you introduce valve train components like the Jessel rocker system, single tapered pushrods and the exotic valve materials and super good valve springs why not bump the valves open more Isn't hopping up a motor basically about getting more air and fuel into the motor so it will make more power.(IE: heat via a controlled explosion)