COMP Cams 11-423-8 Xtreme Energy 224/230 Hydraulic Roller Cam for Chevrolet Big Block 396-454 Great for street machines, needs intake, headers, 2000+ stall and gears. 1,900-5,600 RPM Operating Range 224/230 Duration at .050". 110 Degree Lobe Separation Angle .510"/.510" Valve Lift Excellent performance in street carbureted applications. Quicker opening lobe profiles deliver increased responsiveness and more area under the lift curve. More vacuum allows an increase in duration for improved performance and assists power brakes. Best performance with aftermarket intake manifolds, headers and lower gear ratios. Fits Chevrolet 396-454 Mark IV Big Block