checking valve to piston clearance

hi, at TDC/overlap stroke is where you need to check clearance. on the exhaust, 20 deg before to TDC. on the intake, TDC to 20 deg, after. this is where the valves will be the closest to piston. for accurate results, degree cam in motor. when you line up the two timing marks, you are on #6 TDC firing. rotate motor one full turn will bring you up on #1 TDC firing. now you can degree cam in and check P/V clearances by rotating crank over.