Will fit ALL 6BT 5.9L 24V motors from1998.5 - 2007. These are a perfect for performance builds using aftermarket camshafts or even for those spinning higher RPM's that do not want valve float. These springs are not so stiff to wear down the lobes on your cam, while providing enough pressure to be suitable for Higher RPM performance applications. These springs will work for all OEM cam lifts. If using an aftermarket cam, please determine your coil bind and make sure these springs match those specs. NOTE (5/5/18): Our manufacturer has changed their process some what, so now our springs are lighter in color. Our previous springs were shot peened and then heat treated to relieve stress. Heat treating creates a darker spring surface. Now they are heat treated, then shot peened and the shot wi.
