COMP Cams Conical Valve Spring Kit GM LT1/LS .660in/.932in DiaThe . 675" Lift Conical Spring Kit with Tool Steel Retainers for GM LT1 LS7 Applications features a smaller diameter in the upper half to reduce active mass. This reduction in mass, along with the progressive frequency created by the conical shape, dampens coil oscillations better than any other spring design. These improvements in dynamic stability allow for the use of more aggressive Camshafts and an increase in RPM limit speed. Finally, Superfinish