Older standard shims will not hold up to the extreme spring pressures and high RPM found in today's engines. COMP Cams offers a simple but effective solution to this problem and a thin, hardened Steel alloy seat which will not only protect the head and shim but will also locate and hold the spring in place. Adding to an already extensive line of locators, COMP engineers have created two new ones specifically for LS Applications. This set of locators (#4872-16) is designed for COMP Beehive Springs with .520" guides (#26918). Designed to handle the extreme spring pressures and high RPM found in today's enginesID locator Oldsmobile springs in place for more stable valve trainEngineered to exact tolerances to ensure prefect fitmentTwo new options designed for LS Beehive and Dual Valve Springs with .520" guides