MBRP 2001-2005 Chev/GMC Duramax 6.6L Regular Cab 4in Extension-Pipe AluminizedSome folks are just not satisfied with the usual. They have to always be pushing the limits; refining and adjustments; until they have the truck that has no limits. We have put together some components that will take your truck to the next lever. This Part Fits: Year Make Model Submodel 2001 2005 Chevrolet Silverado 2500 HD Base 2001 2005 Chevrolet Silverado 2500 HD LS 2001 2005 Chevrolet Silverado 2500 HD LT 2004 2005 Chevrolet Silverado 2500 HD WT