Please check notes in each part listing to ensure the Fuel Line Connector is correct for your 1999 GMC SIERRA 2500 with a 6.0L engine. Special restrictions like "California only" or "with sport package" may indicate a Fuel Line Connector fits only certain 1999 GMC SIERRA 2500 models.
Clicking a "More Info" link will display a picture and/or other details about that Fuel Line Connector in a separate window (you may need to turn off your pop-up-blocking software for this to work).
After choosing a Fuel Line Connector, 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 Fuel/Air parts, other GMC SIERRA 2500 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 1999 GMC will not be lost if you switch.