[VADER SS L99]

On the debate of underhood temps with headers vs manifold. If your talking mild steel headers vs cast Iron Manifolds then yes, absolutly does the stock manifold keep heat down over the header but on stainless steel it will be a different story. Stainless Steel probably holds the heat in just as well as the stock cast iron manifold and a coated stainless steel header probably holds it in better. If I were not right then I see no way the new Ford Mustang or Toyota Tundra would get a shorty stainless steel header from the factory.