Please excuse if this is a noob question. Part of measuring the valve clearance is to "feel" the drag on the gauge between the shim and rocker for the openers. On the vertical cylinder, part of the drag is caused by the weight of the rocker. Wouldn't this lead to inaccurate measurements? Wouldn't it make more sense to measure between the cam and rocker? This way the drag being felt is truly only caused by the gap between cam and rocker and not the weight of the rocker?