.660-Inch Dual Valve Spring Kit for LS Engines

The Texas Speed & Performance .660" Polished Dual Valve Spring Kit, featuring American-Made PAC Racing springs, is engineered to provide excellent valvetrain control for aggressive hydraulic roller camshafts in Chevrolet Gen III IV LS engines (5.3L, 5.7L, 6.0L). This kit utilizes PAC's polished dual valve springs, which enhance durability and stability by reducing the chances of spring fatigue and failure while maintaining full pressure. Key components include PAC Racing polished dual valve springs rated to .660" lift, titanium retainers, and a patent-pending Precision Race Components integrated seat/seal. This integrated design eliminates the need for separate valve seals, simplifying installation and preventing tearing or displacement of seals. The kit's specifications include an installed height of 1.810", closed spring pressure of 160 lb. @ 1.810", and open spring pressure of 415 lb. @ .660" lift. The maximum spring lift is .660" with a coil bind at 1.015". Important compatibility notes: This dual valve spring kit uses GM factory valve stem locks (not included). It will not work on LS7, LS9, any Gen 5 LT1/4 engine applications, and most aftermarket cylinder heads with bronze guides. The integrated seat/seal works with factory-size valve guides only and cannot be used on aftermarket bronze guide applications.