Experience performance and durability with the enhanced Duramax exhaust manifolds, specifically designed for the 2001-2016 6.6L Duramax engines. The BD upgraded manifolds not only remove the flow restriction found on the 2001-2006 model driver’s side manifold, but they also increase overall flow on both manifolds by 5%! Crafted with precision, the BD manifolds feature robust, 65% thicker designed castings constructed from high-silicon ductile iron to combat warping and cracking. Designed to be a one-stop drop-in kit, including all fasteners and gaskets needed to make installation quick.This Part Fits:YearMakeModelSubmodel2006-2016ChevroletExpress 2500Base2006ChevroletExpress 2500LS2006ChevroletExpress 2500LT2006-2016ChevroletExpress 3500Base2011-2016ChevroletExpress 3500LS2011-2016ChevroletExpress 3500LT2001-2005ChevroletSilverado 2500 HDBase2015-2016ChevroletSilverado 2500 HDHigh Country2001-2006ChevroletSilverado 2500 HDLS2001-2016ChevroletSilverado 2500 HDLT2007-2016ChevroletSilverado 2500 HDLTZ2004-2016ChevroletSilverado 2500 HDWT2001-2005ChevroletSilverado 3500Base2001-2006ChevroletSilverado 3500LS2001-2006ChevroletSilverado 3500LT2004,2006ChevroletSilverado 3500WT2007ChevroletSilverado 3500 ClassicLS2007ChevroletSilverado 3500 ClassicLT2007ChevroletSilverado 3500 ClassicWT2015-2016ChevroletSilverado 3500 HDHigh Country2007-2016ChevroletSilverado 3500 HDLT2007-2016ChevroletSilverado 3500 HDLTZ2007-2016ChevroletSilverado 3500 HDWT2006-2016GMCSavana 2500Base2006-2016GMCSavana 3500Base2011-2016GMCSavana 3500LS2011-2016GMCSavana 3500LT2002-2005,2015-2016GMCSierra 2500 HDBase2011-2016GMCSierra 2500 HDDenali2001-2002,2006GMCSierra 2500 HDSL2001-2016GMCSierra 2500 HDSLE2001-2016GMCSierra 2500 HDSLT2003-2014GMCSierra 2500 HDWT2002-2005GMCSierra 3500Base2001-2002,2006GMCSierra 3500SL2001-2006GMCSierra 3500SLE2001-2006GMCSierra 3500SLT2004-2006GMCSierra 3500WT2015-2016GMCSierra 3500 HDBase2011-2016GMCSierra 3500 HDDenali2007-2016GMCSierra 3500 HDSLE2007-2016GMCSierra 3500 HDSLT2007-2014GMCSierra 3500 HDWT