Please check notes in each part listing to ensure the Headlamp Assembly is correct for your 2001 GMC SIERRA 3500 with a 6.6L DIESEL Turbocharged engine. TYC & DORMAN are competing brands, and each brand's Headlamp Assembly may be interchangeable. Special restrictions like "California only" or "with sport package" may indicate a Headlamp Assembly fits only certain 2001 GMC SIERRA 3500 models.
Clicking a "More Info" link will display a picture and/or other details about that Headlamp Assembly in a separate window (you may need to turn off your pop-up-blocking software for this to work).
After choosing a Headlamp Assembly, click the "Add Part" button. Shipping costs will be shown on the Shopping Cart page. You may use your browser's Back button or click "Find More Parts" to find more Body parts, other GMC SIERRA 3500 parts or parts for a different vehicle. Please try our Interactive Catalog (click link above) for faster searching. Both catalogs use the same shopping cart so any auto parts you've already chosen for your 2001 GMC will not be lost if you switch.