In Treadstone Performance's never ending quest to expand our inventory to include almost every possible product desirable to aid in the turbocharging of your vehicle, Treadstone Performance is proud to introduce our investment cast SR20 heat flange. Our casting methods are using the latest in turbocharger-manifold technology with state of the art investment cast process and CAD based techniques. Designed using Solid Works and optimized for ideal fitment and finish, they benefit from an exclusive investment casting method utilizing extremely durable 304 stainless steel. Nissan SR20 Investment Cast Stainless Steel Head Flange. We designed this flange to streamline exhaust gases from a oval port to circular port and match the exact size of our 1.5" nominal weld els. Also we created cut outs on the back side of the flange, not only does this reduce the weight of the flange, but it aids in sealing the flange to the head with approx 35% more sealing pressure. Pressure = Force/area, so if we reduce the area, given the same clamping bolt force, the sealing pressure increased! Never will you have an pesky exhaust leak again. The top of the flange also features a rib that runs through the middle of the flange, this high point in the flange resists warping when welding and maintains a high level if structural rigidity. Our casting methods use the latest in turbocharger-manifold technology with state of the art investment cast process and CAD based techniques. Designed using Solid Works and optimized for ideal fitment and finish, they benefit from an exclusive investment casting method utilizing extremely durable 304 stainless steel. Click Here For More Info!