Chevrolet Gen III/IV LS-Series 3-Bolt Advertised Duration: 272/272 Duration @ .050": 222/222 Valve Lift w/1.70 Rockers: .561/.561 Lobe Separation Angle: 113 Intake Centerline: 109 Valve Lash: Hyd./Hyd. 1800-6500. Street/strip power, great mid range with top end performance, ok with turbocharger.