Where is the TDC marker on a 1999 gmc savana van with a 5.7 engine?

On a 1999 GMC Savana van with a 5.7L engine, the TDC (Top Dead Center) marker is typically located on the harmonic balancer or the timing chain cover. You can often find a notch or a mark on the harmonic balancer that aligns with a corresponding mark on the timing cover at TDC for cylinder number one. To confirm TDC, you can remove the spark plug from cylinder one and use a tool to feel for the piston at its highest point.