Camshaft - 561 - Evolution Big Twin

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 80"-96" engines at 9.5:1-10.5:1 compression ratio. Provides strong midrange power, 3000-5500 rpm. Works with hydraulic tappets. Requires high-lift springs. Spring spacing required. Made in the USA. Installer must check coil bind, valve-to-valve clearance, valve-to-piston clearance and cam lobe to case clearance..