Adjust valve lash on 5.7 vortex with motor not running?

To adjust the valve lash on a 5.7 Vortec engine with the motor not running, first, ensure the engine is cool and remove any necessary components for access. Rotate the engine to top dead center (TDC) on the compression stroke for the cylinder you’re adjusting. Loosen the adjusting nut on the rocker arm, then use a feeler gauge to set the correct lash, typically around 0.006-0.008 inches for intake and 0.008-0.010 inches for exhaust. Tighten the nut while holding the pushrod until the desired resistance is felt, then repeat for each cylinder.