To be certain, you should:
1. Consult your owner's manual: This is the best source for the specific location on your vehicle's engine.
2. Look at a repair manual specific to your Silverado's engine: A Haynes or Chilton manual, or online resources like AllDataDIY, will have diagrams showing the location.
3. Use a search engine with images: Search for "2007 Chevy Silverado [your engine size] oil pressure sending unit location." This will often bring up images that can help you pinpoint it.
Be cautious when working around the engine. Ensure the engine is cool and disconnect the negative battery terminal before starting any work.