Here at Xtreme CFM, we start out with a very durable casting which provides us with a solid foundation where we are able to transform these heads into a work of art and do what we know best to do, provide you with the most power producing head out there. Only available exclusively through Xtreme CFM. These heads flow over 400cfm on the intake! All xtreme cfm cylinder heads have gone through extensive research and development to provide you with the most powerful "out of the box" heads available on the market. In development, our main objective was to provide the highest flow possible without ever sacrificing air speed in…