When tuning its often recognised that cam shafts make the most dramatic changes in engine performance. Cam shafts when used correctly change the engines entire characteristics, its so important to know what you want cam shafts to do before you start shopping. The choice is further complicated if your cams can be dialled in often referred to as cam shaft degreeing. Apart from head compatibility, the two main factors in cam choice is Lift & Duration, cam shaft materiel also effects performance as in inertia & friction but firstly you select the best lift & duration to give you what you want or often closest to what you want. Above is 3 sets of ZX10R cams, the pair pictured bottom are stock Kawasaki cams, the pair pictured right are stock Kawasaki cams re-ground by Kent cams to Kawasaki racing cam profile, the above pair are all bells & whistles high grade light weight custom profiled cams manufactured by Kent Cams.