High revving engines need the extra protection of dual valve springs. Most high performance single valve springs will prevent valve float below 6000 RPM. Engines that are designed to hit 6500 RPM should be equipped with #1491 Dual Hi-Rev Valve Springs.

The Dual Hi-Rev Valve Springs supplied by CB are manufactured of silicone treated steel to help stand the stress of high performance driving.

INSTALLATION NOTE: It is necessary to machine the cylinder head valve spring boss before installing dual valve springs.