The new Ferrea Valve Springs are processed with premium-grade alloy and feature special thermal treatment. Ferrea's advanced spring design and material specs have uniform load and stress distribution even in the most extreme racing conditions. Great for high revving applications. These valvesprings and retainers will reliably allow your engine to rev high without the worry of part failure, valve float, or coil bind. Aftermarket valvesprings are made out of superior metal alloy's and optimized spring rates to make sure your valvetrain can keep up with your cams at high RPM. Whether you are rebuilding your engine, or building an all out race engine, replacing your valvetrain with Ferrea components will allow you to rev higher, and go more aggressive on your cams.