The COC-4757 is Comp Cams 1.500” OD X 0.645” ID valve spring shim kit. The kit includes a total of 48 shims (0.015” thick qty 16, 0.030” thick qty 16 and 0.060” thick qty 16).
The shims are manufactured from high quality shim stock and heat treated to stand up to radical cam lobes. The shims perform two functions, first is to reduce the chance of damage to the spring pocket of the head from the valve spring and secondly, they are used to achieve the correct installed spring height.
