Where is the camshaft sensor on a 96 Chevy 350 vortec?

The camshaft position sensor (CMP sensor) on a 1996 Chevy 350 Vortec is located on the passenger side of the engine block, near the front of the engine, and below the distributor (if equipped, some Vortecs had distributorless ignition systems). It's usually mounted in a boss or bracket on the engine block itself. You'll likely need to look carefully; it's a relatively small sensor.