PAC-1234X Beehive Valve Spring for 5.0L Coyote

The PAC Racing Springs PAC-1234X valve spring is an ovate wire beehive spring engineered for performance applications in Gen 1 and Gen 2 Ford 5.0L Coyote engines. These springs are designed as a drop-in replacement, offering an improved 92 lbs load at the 1.575-inch installed height compared to factory spring configurations. The beehive design helps reduce valvetrain mass—weighing 33.50 grams—to support improved engine stability and reliability during high-RPM operation. Technically, these springs provide a spring rate of 240 lbs/in and are rated for a maximum valve lift of 0.575 inches, with a coil bind height of 0.940 inches. They feature an outside diameter of 1.021 inches at the large end and 0.848 inches at the small end. The ovate wire construction is a signature of the RPM series, intended to manage harmonic stress and fatigue effectively in high-performance valvetrains. As a drop-in component for the Coyote 5.0L, they are compatible with factory cylinder head architectures for specified generations.