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 drivers 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.