Magnum 292H Hydraulic Flat Tappet Camshaft Lift: .550''/.550"Duration: 292�/292�RPM Range: 2500-6500 *Note: In order to use these camshafts in 1965-66 396/427ci blocks, it is necessary to machine a 3/16'' wide x 7/64'' deep groove in the rear main journal of the cam to allow oil flow to the top of the engine.Street/Strip napplications. 10:1+ compression, 3000 stall converter or 4-speed, 4.10:1 or lower gears & aftermarket intake. Very rough idle.Operating Range:2500-6500 RPMDuration Advertised:292° Intake / 292° ExhaustDuration @ .050'' Lift:244° Intake / 244° ExhaustValve Lift w/1.7.