To be certain, you should:
1. Consult your vehicle's repair manual: This is the most reliable source. The manual will have diagrams and precise locations.
2. Use an online parts diagram: Many auto parts websites (like AutoZone, Advance Auto Parts, etc.) have diagrams you can access by entering your vehicle's year, make, and model. These diagrams show parts locations.
Searching for "[Your Engine Size] 1998 Chevy 1500 Camshaft Position Sensor Location" on Google Images might also reveal helpful pictures.
Remember to be cautious when working around the engine. Disconnect the battery's negative terminal before starting any work.