Competition Cams 35-514-8 Xtreme Energy Computer Controlled XE266HR-12 Camshaft for Ford 5.0L Engine Originally Equipped with Hydraulic Roller Cams HYDRAULIC ROLLER - Xtreme EnergyComputer Controlled: Mild modifications, 3.27-3.73 gear, mass air, larger throttle body. 266/274 Advertised Duration, 216/224 Duration @ .050 inch, .544 inch/.555 inch Lift, 112 Lobe Separation Valve spring upgrade required