561 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, For motors with up to 10:1 compression, Very good mid-range performance, Works with hydraulic tappets, Requires high-lift springs, 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.