631 Cam – Evolution
S&S Cams are tested on the dyno, street and track before being offered to the public, With hundreds of hours of testing on each cam, you know you are getting the best cam S&S can produce, Makes best power from 4500 rpm and up, Works with solid or hydraulic tappets, Requires high-lift springs, For all high-compression engines 11:1 and up compression, Installer must check coil bind, valve-to-valve clearance, valve-to-piston clearance and cam lobe to case clearance., Made in the U.S.A.