Check how much piston rock you have, stick a clean wooden dowl on the bottom of an installed piston and push up and measure that way on both sides. Bore size, piston to bore clearance, piston skirt height, bearing clearance can all add up to a supprise, basing it off a calculated clearance is silly or even a static center of the bore measurement. Useing this method I run pretty much any motor at .020 clearance and never had an issue. Measureing this way will give you more of an actual running minimum clearance than taking rod center to center-piston heaght-stroke-deck height or even more acurate than measureing at the center of an idle/static unloaded piston. My only disclaimer is I have only built one aluminum rod engine and it had no quench to speak of so if your useing an AL rod you need to consider that.