With a .650" maximum lift, these Beehive Valve Springs were designed for Ford 4.6L and 5.4L Modular 2 and 3 Valve engines and Duramax applications. COMP Cams Beehive Valve Springs deliver increased valve train stability and a much lighter valve train. This is achieved with less spring pressure for better valve control and reduced weight of both the spring and retainer. The unique Beehive shape handles valve train stress more efficiently to eliminate damaging harmonics and increases high RPM horsepower and durability. The oval/multi-arc wire shape places the maximum area of the wire at the point of highest stress to handle valve train stress more efficiently and allow better heat dissipation for longer life. Because of the unique Beehive design, the valve train can handle more RPM and more aggressive cam profiles.