Porting heads is an art and science. It takes a craftsman's touch to shape the surfaces of the head for the optimal flow characteristics and the best performance. Porting demands the right tools, skills, and applicationof knowledge. Few other engine builders have the same level of knowledge and skill porting engine heads as David Vizard. All the aspects of porting stock as well as aftermarket heads in aluminum and cast-iron constructionsare covered. Vizard goes into great depth and detail on porting aftermarket heads. Starting with the basic techniques up to more advanced.