Competition Cams 12-211-2 Magnum 270H-10 Camshaft for Small Block Chevy HYDRAULIC - Magnum: High performance. Biggest cam with stock converter but better with 2000+ stall. Use lower gears. Mild rough idle. 270/270 Advertised Duration, 224/224 Duration @ .050 inch, .470 inch/.470 inch Lift, 110 Lobe Separation Valve spring upgrade required