High-performance racing camshafts, Stage 1 and Stage 2 performance camshafts are drop-in cams that are designed to be used with stock valve springs, In most applications, Stage 1 cams deliver more torque and Stage 2 cams provide more peak horsepower, Select cams feature Hot Cams Improved Throttle Design (ITR) technology; these cams improve throttle response throughout the entire rpm range while providing excellent power gains through the mid-range and top-end