TSP Stage 2 5.3 VVT Truck Camshaft212 218, . 600" . 600", 112 LSA The 2007. 5+ truck engines utilize Variable Valve Timing (VVT) controlled via a cam phaser. A cam phaser is a computer controlled cam gear that automatically optimizes camshaft timing based on the current engine RPM. While this technology provides tremendous efficiency benefits, it presents a challenge when designing performance cams due to the wide range of valve timing movement and constantly changing piston to valve