Kibblewhite valve springs are designed using sophisticated, proprietary design and simulation software. That, as well as 70+ years of experience helps to determine critical characteristics, including stress, natural frequency, system harmonics, and fatigue life. Kibblewhite valve springs are made out of super-clean chrome-silicone valve spring wire and go through a heat treatment, stress-relief, and shot-peening process to allow Kibblewhite to bring you the best valve springs on the market in multiple styles, such as standard, high-lift, and beehive.