8. The flat-tappet lifters Troutman prefers to use with the cam are Comp Cam’s Performance Series lifters with an EDM oiling hole in the face of the tappet. These are “chilled iron” lifters, which can be a few grams heavier than tool steel lifters, but Troutman believes the iron material mates better with the cam for improved lobe life. This is critical since the extremely aggressive lobes being used in today’s LMS engines are often right on the edge of failure if they aren’t matched perfectly with the flat tappet lifters. Any lifter deformation that causes the edge of the lifter to touch the lobe means your engine will become a giant paperweight very quickly.