[crainholio]

I've been spending a lot of time under my LS1's valve covers lately, and it's very likely the piece of debris is hung up against the #2 valvesprings waiting for you to come in and get it.

Before doing anything: blow off the top of the engine and the area around the valve cover with compressed air. Get all the small dirt and grit away from the area you're opening.

Disconnect battery, gently remove plug wires from the 4 coils, disconnect the coil pack harness, unbolt the coil pack, unbolt the valve cover, you're off to the races.