Remove both valve covers and all the spark plugs to make the motor easier to turn over. Put a socket on the harmonic damper retainer bolt head with a long ratchet bar so the motor is easy to turn over by hand. Turn the motor clockwise until the intake valve on #1 is fully open (spring compressed). Now, turn the crank one full turn and release the pressure on the rocker of that valve until the pushrod is loose. Grasp the pushrod with the thumb and forefinger of your left hand an jiggle it straight up and down, but with NO pressure. Slowly tighten the rocker nut while jiggling the pushrod. If you push down with any pressure whatsoever, you can begin to depress the internal spring in the lifter, which you DO NOT want to do. Just take up the play between the lifter pushrod cup and the underside of the rocker arm. When you have eliminated all the play, give the nut 1/2 additional turn clockwise. Now, turn the crank 1/4 turn (90 degrees) clockwise and adjust the intake valve on #8 cylinder. Now, another 1/4 turn and adjust #4 intake, then just follow the rest of the firing order while turning the crank 1/4 turn each time. 1-8-4-3-6-5-7-2. After you've done all the intakes (it helps to stand at the side of the motor to determine which valve is the intake and which is the exhaust, or get a Motors Manual and lay it out to look at), start back at #1 cylinder, fully depress the exhaust valve, turn the crank one full turn clockwise and adjust it. Continue the same way for all the exhaust valves and you should be ok.
