The Colt Cams Tappet Set has been custom designed to deliver the best possible performance for your 5.9|6.7 Cummins engine. With a focus on maximizing the rotation of the crown, these tappets have been custom crafted to provide optimum results. Additionally, inconsistencies in the crown have been addressed to ensure that you get the most consistent performance possible. With measurements similar to standard tappets, this is an easy and effective way to upgrade your engine without having to make significant changes.