In some endurance and oval track applications, it is necessary to use a rev kit to precisely follow the profile of the cam. This safety measure ensures that in the event of pushrod breakage or rocker arm failure, the lifter will not come out of the bore. This could cause a loss of oil pressure and subsequently, engine failure. COMP Cams Rev Kits are made from tough extruded aluminum and should require no machine work. The kit comes with all necessary springs and buttons.