If you live in colder climates or are having trouble getting started after you switched to headers, then the fuel and air are too cold to mix properly. With our heat riser kit, coolant runs to the bottom of your intake manifold to warm it just as the exhaust manifold once did. They were orginally bolted together for this purpose. This aluminum plate bolts on easily and comes with hose and clamps. Use liquid sealant or a gasket to seal.