TrackMax Lightweight Horizontal Bar Chevrolet Mark IV, Gen 5 Mech Roller Lifters All new tooling. Lightweight, almost 20% lighter than most other mechanical roller lifters. Features CNC machined alloy bar stock bodies with case hardened 8620 rollers. Spring loaded, self lifting design for easy cam changes is what make these lifters so popular. Fully rebuildable. Made in the USA!