Valve Spring Locator Valve Spring Locator; 16 pc.; Thickness 0.060 in.; I.D. 0.520 in.; O.D. 1.300 in.; Spring I.D. 0.640 in.; FEATURES: Thin Hardened Steel Alloy Seat Protects The Head And Shim Holds The Head In Place Machined Head 1 Year Limited Warranty The 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(R) 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 required that the head be machined a great deal to accept this cup so COMP(R) now offers an I.D. locator with the locating shoulder on the inside, as well as the spring cup. Many sizes are available to locate from the inside or outside diameter. COMP Cams manufactures truly superior hydraulic and solid flat tappet, hyd and mechanical roller, and overhead camshafts for everything from OE replacement to full race, designed and manufactured using cutting-edge technology and the finest engineering in the industry. Whether your engine is naturally aspirated, or you run nitrous, or a supercharger or turbo, our cams make more horsepower than any other. Looking for that ultimate hard-hitting muscle car idle? Check out our aggressive new Thumpr Cams. Match our camshafts up with our competition-grade lifters, valve springs, timing sets, and other supporting components, and you'll experience the ultimate in race-winning reliability!