Mid to upper range cam for bolt-on blowers running higher boost psi. Major power gains above 4900 RPM, compatible with stock springs. Best with 3.73+ gears & 2500 stall. Great idle. Works with stock tune. 1,500-5,800 RPM Operating Range 222/239 Duration at .050". 116.5 Degree Lobe Separation Angle 0.450"/0.450" Valve Lift Blower Ready - Grind is designed specifically for use with supercharged engines. NSR- No Valve Spring Upgrade Required. Fits Ford 4.6/5.4L Modular 3 Valve Made in USA