1968 - 72 Chevelle, El Camino, Monte Carlo, Big Block headers. Made from 304 stainless steel for maximum corrosion resistance. All tubes are CNC mandrel bent for optimal flow. These headers have 2 primaries with CNC laser cut 38 thick flanges. With 3 - 12 Slip - fit collectors. These headers fit perfectly. Long tube design provides awesome torque and street performance. Recommended to use a mini - starter for additional clearance. Mill finish, All TIG welded for strength and durability. These kits come with a lifetime warranty and proudly made in the USA.