Speedtech Performance Stainless Headers are made to work exclusively with the Speedtech Sub Frame in 1967-69 F-Body and 1968-74 X-Body GM Cars. All tubes are CNC mandrel bent .065 wall 304 stainless steel. The large primary tubes are tig welded to CNC laser cut flanges for a precise fit. The long tube design promotes increased low end torque while providing excellent street performance and ground clearance. An integrated merge spike increases power, improves sound quality and promotes better scavenging. Gaskets and Fasteners are not included.