Cam HP capability

Actual valve lift is easiest when measured. Simply it's the difference between cam lobe lift, and the movement of the valve itself. So the things like lash on a solid or solid roller cam, angle of the pushrod, quality of the rocker, and quality of the rocker geometry and valve job all come into play. That's why it's easiest measured. But it can be measured with any cam once the valve job and mock up is done. Once you have the loss, you can use that figure as aguide to order the cam you want if you're that picky. Or what I do is say you'll lose about "x" and go from there. Going a little taller isn't a big deal. Changing duration could be.