Where is the pcv valve location for 2003 chevy express van?

almost all crankcase vent valve,s are located in a valve cover. follow the large vacuum hose coming from the intake manifold [ where all the vacuum originates]...to the crankcase vent valve...there are a few [ usually small in diameter] except one that lead,s to the power brake booster [ if so equipped] but besides that the P.C.V. is the next largest as far as vacuum hose,s go...there is one to the E.G.R. valve but it is usually smaller. you will know when you see it's attached to a small , one way, vacuum valve inserted into a rubber grommet. they are usually easily cleaned out with a mild solvent such as brake cleaner or carburetor cleaner. ...hope this helps...best of luck!