Ferrea is one of the most well-known names in the aftermarket valvetrain industry. That is because they make the finest quality valvetrain available! Ferrea valvetrains are trusted by top racing teams around the world. Formula 1, Nascar, Indy, drag racing, and road racing teams all utilize Ferrea valvetrains in some of the world's highest performing engines. It is definitely a notch above the rest. Heavy duty valve springs will prevent valve float at higher rpm. Titanium retainers will help keep the weight down, while providing extra strength.