A popular, easy way to advance or retard the cam is with Mr.Gasket's bushing kit. The bushings can be used to advance the cam for increased low-end torque and midrange horsepower. They can also reduce excessive low-end torque and increase top-end horsepower by retarding the cam. The kit includes four offset bushings and a 0 degree bushing, so stock timing can be used again if desired. Cam sprocket dowel pin hole must be drilled .406", (13/32") diameter. Fits Ford 289-302 cu.in. includes case-hardened dowel pin 2,4,6,8 degrees plus a 0 degree bushing.