COMP Cams Spring SeatsEb 1.300in X .800in - Set of 100The older style standard shims will not hold up to the extreme spring pressures and high RPM found in racing engines being built today. COMP Cams offers a simple but effective solution to this problem a thin, hardened steel alloy seat which will not only protect the head and shim but also locate and hold the spring in place. Previously, this part has been available only in a cup form with the retaining portion being on the outside of the part. This