Competition Cams 12-214-4 Magnum 305H-10 Camshaft for Small Block Chevy HYDRAULIC - Magnum: Pro Street/bracket, limited street driving. Intake, gears, 3500+ stall. Racy idle. 10.5:1 compression. OR Drag Race: 3500-4000 stall or 4 speed with 11:1+ compression. 305/305 Advertised Duration, 253/253 Duration @ .050 inch, .525 inch/.525 inch Lift, 110 Lobe Separation Valve spring upgrade required