This "high-lift" cam for modified knuckle engines features .420" valve lift and increased duration for larger engines up to 93" and compression ratio of up to 8.5:1. Special high-lift valve springs are required. Cam opening/closing: Intake 31°/55°; Exhaust 60°/30° Cam duration: Intake 266°; Exhaust 270° Lode centerline: Intake 102°; Exhaust 110° Max Valve Lift: Intake .420"; Exhaust .420" Valve lift @ TDC: Intake .167"; Exhaust .152"