Outflows the factory exhaust manifolds by 6%, improving performance and throttle response Eliminates the flow restricting pinch of the factory drivers-side manifold 1/8" NPT exhaust gas temperature ports (EGT) ports are incorporated into the exhaust manifolds for gauges or testing equipment Durable cast ductile iron construction This product is not CARB exempt at this time and is not legal for sale in California or use on vehicles registered with the California Department of Motor Vehicles