To be certain, I strongly recommend:
* Consulting your owner's manual: This is the best resource for the precise location and oil change instructions.
* Looking up a diagram online: Search for "[your engine size] 2003 Chevy Silverado 1500HD oil filter location" on Google Images or a similar site. Many diagrams clearly show the filter's position.
Don't rely solely on general information; always verify the location before attempting an oil change.