With a .600" maximum lift, these Beehive Valve Springs were designed for hydraulic or Solid flat tappet cams as well as hydraulic Roller cams. They allow Big block engines to turn more RPM. 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 Camshaft profiles.OD 1.059/1.444ID .650/1.000Seat Load 155 @ 1.880Open Load 377 @ 1.280Coil Bind 1.230Rate (Lbs./In.) 370Titanium Retainer 794Steel Retainer 795Cup Seat 4696, 4697, 4698Shims 4754