Where is the crankshaft position sensor located on a 2001 Chevy Silverado 3500 crew 4X4 8.1 engine?

The crankshaft position sensor (CKP) on a 2001 Chevy Silverado 3500 with the 8.1L engine is typically located on the passenger side of the engine block, near the front of the engine, below the distributor (if equipped). It's often mounted fairly close to the crankshaft pulley.

However, precise location can vary slightly depending on the specific engine configuration. It's best to consult a repair manual specific to your vehicle's year, make, model, and engine (the 8.1L) for a definitive diagram and location. A repair manual will often have photos and detailed instructions. You can find these online or at auto parts stores.