The 0.045 clearance is side clearance, not end on & it is the intake so it's closest when opening, so the piston is rapidly going away from the opening valve. I retarded the cam centerline 0.5* & retested it with new plasticine. The side clearance may have gained 0.010 but the depression barely went 0.030 deep. I think I can live with that, it just means the cam centerline is limited to 103*. with these pistons as they are. I had run this cam at 105* before & found clearance more than adequate, 102.5* is just a bit close for Peace of Mind