Ferrea EVO VIII 8 03-07 4G63T 95lbs DUAL Valve Springs TI retainers Kit KT4013

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.

Ferrea is the top of the line when it comes to valves springs and retainers. If you google "Ferrea" you would be hard pressed to find anyone say anything bad about them. They are not the cheapest on the market, but if you want the best, Ferrea is the way to go.

There are 3 Major Issues with stock valvetrain, that can be prevented by using Ferrea Components.

• BIND - They can "bind" and get stuck, losing their ability to open and close the valve. This is an easily diagnosable failure. Depending on how it binds, it could cause failure to other engine parts.

• BREAK - They can "break" into pieces dropping the valve into the combustion chamber and consequently ruining your bottom end.

• FLOAT - "Valve Float" is a hard to diagnose condition where the valve spring rate is not high enough to fully extend the spring and close the valve after a complete rotation of the cam before the cam comes back around again. So what ends up happening is that when the cam is spinning fast (high rpm) the valve never closes, and combustion leaks out of the engine, and the engine loses power.

Our springs are heat-treated and stress relieved, which dramatically increases the spring’s life. Our valve springs provide the stability needed for high lift, high rpm racing engines, while minimizing the load loss for today’s aggressive valvetrain combinations.

We currently offer four different types of retainers to choose from: Titanium, Lightweight Tool Steel, Steel and Aluminum Magnesium retainers, all of which are CNC machined to perfection and offer superior strength and stability. 

Ferrea takes great pride in offering premium quality Spring Seat Locators. Fully CNC machining in-house from 4140 chromoly alloy for different applications. Each piece is crafted to exact tolerances OD & ID specs and insure flat, parallel spring pad to the bottom surface. Heat treatment consists of a hard Nitrided surface for unmatched toughness and anti-wear characteristics.