K Motion K800 Dual Chevy Size Valve Springs

Why are these K-Motion Valve springs the choice of so many winning circle track and drag racers? K-Motion springs are coiled from the finest chrome silicon or H-11 tool steel and then heat treated and or stress relieved to the correct Rockwell hardness for each application. The springs are then visually checked for tool marks or pits and dampers are radius ground and de-pointed for longer life. Each spring is pressure checked and boxed with no more than five pounds variation per box. Here are the technical specs: O.D./I.D; 1.460; App; R ; Max Lift;.700; Spring Type; Silicon Dual; Seat Pressure; 155/1.850; Open Pressure; 450/1.150; Coil Bind;1.085
Sold in sets of 8.