Intended for camshaft replacement for motors that have already been converted to an S&S gear drive systemBroad torque curve improves output over stock over the entire rpm rangeBolt-in for 103'' engineMade in the USARequires the use of high-performance valve springs.Due to the inherent characteristics of gear drives, there may be more valve train noise.Installer must check coil bind, valve-to-valve clearance and valve-to-piston clearance.