What the procedure for adjusting the valve on a Chevy 396 motor?

To adjust the valves on a Chevy 396 motor, first, ensure the engine is at top dead center (TDC) on the compression stroke for the cylinder you are working on. Then, loosen the locking nut on the rocker arm and turn the adjusting screw until you achieve a slight resistance while spinning the pushrod with your fingers, typically around 1/2 to 3/4 of a turn past zero lash. Finally, retighten the locking nut while holding the adjusting screw in place. Repeat this process for each cylinder in the correct firing order.