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. Gold Series camshafts are designed to provide extra torque and horsepower; these camshafts require the use of stiffer valve springs. New Builder Series camshafts offer engine builders a multitude of options for different engine configurations. Builder Series camshafts were developed for engine builders that have specific requirements to maximize their particular engine configuration; see notes in the performance description for use with OE valve springs or the requirement of stiffer valve springs.