The 1999 Chevrolet Suburban utilizes a 350 cubic-inch engine with a standard overhead valve design. Overhead valve means that there is a single camshaft located within the block of the engine that utilizes lifters and pushrods to actuate the valves. Valve lash on this type of engine is the clearance between the valve stem and rocker arm. Setting the valve lash is, in theory, quite simple, but can be very difficult for someone who has never done it before. The process usually takes around three hours to complete.
Start the engine and allow it to reach operating temperature. Shut the engine off and move quickly to step two.
Remove the four bolts securing each of the valve covers and remove the valve covers.
Use a wrench connected to the crankshaft drive gear to turn the engine over until the number one intake valve is at full lift. Adjust the number six intake valve by tightening the intake valve rocker arm nut until the pushrod cannot be spun (signaling that the rocker arm is pressing down on it). Back the rocker arm nut off 1/8-turn.
Continue the process in step three on all intake valves in the following order: number eight intake valve at full lift, adjust number five intake valve; number four valve full lift, adjust number seven valve; number three valve full lift, adjust number two valve; number six valve full lift, adjust number one valve; number five valve full lift, adjust number eight valve; number seven valve full lift, adjust number four valve; number two valve full lift, adjust number two valve.
Use the process in step three to adjust the exhaust valves in the same order as in step four.
Install new valve cover gaskets and reinstall the valve covers.
