Aftermarket camshafts are sold with a specification card that lists the lobe timing, lift, and clearance specifications (on solid lifter cams). Without the "cam card" any engine builder must either guess at the clearance setting or plot a lift curve as I described above. There is a noticeable difference in the rate of lift as the cam lobe transitions from taking up the clearance to actually lifting the valve off its seat. It's very obvious to an experienced engine builder when and where that happens.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
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