Stainless Steel Construction: The headers are constructed out of heavy duty gauge, mandrel-bent 304 stainless steel tubing with a .120" wall for strength and durability. The up-pipes and down-pipe are constructed out of 2" and 3" mandrel-bent 304 brush finished stainless steel tubing.Optimized Tube Lengths: Tube lengths and mitered collectors are optimized for true pulse control technology which improves flow and performance across the power band.Heavy-Duty Flanges: A CNC-machined v-band inlet flange and heavy-duty outlet flange provide a secure, leak-free seal.EGT Ports: Two exhaust gas temperature (EGT) ports are provided with this system. A 1/8 NPT EGT probe port is incorporated into the driver™s side manifold and a M14x1.5 port in the down pipe. This allows for easy installation of sensors, gauges or testing equipment.4" Interlock Flex Pipes: The up-pipes utilizes heavy duty 4" flex tubes with internal interlock liners.Retains EGR Flange: This system retains the EGR flange.Factory Mounting Locations: These headers utilize factory locations making it a true bolt-on system, no cutting or drilling required and includes all necessary hardware for a hassle-free installation.Fitment Note: This item will not fit models manufactured after July 2014 equipped with a 3 bolt flanged down-pipe.aFe POWER exhaust systems are engineered and manufactured in our Corona, California facility.

This Part Fits:

Year	Make	Model	Submodel
2015	Chevrolet	Silverado 2500 HD	High Country
2011-2015	Chevrolet	Silverado 2500 HD	LT
2011-2015	Chevrolet	Silverado 2500 HD	LTZ
2011-2015	Chevrolet	Silverado 2500 HD	WT
2015	Chevrolet	Silverado 3500 HD	High Country
2011-2015	Chevrolet	Silverado 3500 HD	LT
2011-2015	Chevrolet	Silverado 3500 HD	LTZ
2011-2015	Chevrolet	Silverado 3500 HD	WT
2015	GMC	Sierra 2500 HD	Base
2011-2015	GMC	Sierra 2500 HD	Denali
2011-2015	GMC	Sierra 2500 HD	SLE
2011-2015	GMC	Sierra 2500 HD	SLT
2011-2014	GMC	Sierra 2500 HD	WT
2015	GMC	Sierra 3500 HD	Base
2011-2015	GMC	Sierra 3500 HD	Denali
2011-2015	GMC	Sierra 3500 HD	SLE
2011-2015	GMC	Sierra 3500 HD	SLT
2011-2014	GMC	Sierra 3500 HD	WT