Our single springs are crafted from premium Superclean Chrome Silicon Vanadium Steel alloy, ensuring exceptional durability and performance. Each spring is computer-designed to maintain optimal wire stress levels and controlled harmonics, providing superior stability and longevity in extreme conditions. Perfect for high RPM and high-performance applications, Supertech's single valve springs offer unmatched reliability and efficiency. Upgrade Subaru EZ30 H6 (1st Gen) with Supertech's precision-engineered single valve springs for peak performance, without sacrificing quality.