These Power Building Videos Heads, Porting, and Valvetrain videos are triple DVD sets with almost five hours of highly detailed information! They take you step-by-step through the entire valvetrain, featuring cams, lifters, springs, pushrods, heads, and more. You'll learn about reading cam cards, cam degreeing, what lift and lobe and duration are all about, and how to choose the right cam for you. These videos also discuss different types of lifters, rocker arms, rocker studs, valve springs, retainers, locks, intake and exhaust runners, which tools you'll need, and how to use them! Numerous types of heads are put on a flow bench and tested to show the flow differences between different heads. If you've ever wanted to learn about heads and valvetrains, these videos explain them firsthand in detailed, plain, easy-to-understand language.