COMP Cams Timing Chains 3101 COMP Cams Hi-Tech Roller Race Timing Sets include cast iron camshafts gears, induction hardened billet steel crank sprockets, and pre-stretched, heat-treated double roller chains with heavy-duty large pin design. They feature 3 keyway crank sprockets for 4? incremental adjustability with 4? maximum advance or retard. These timing sets are dynamically balanced and quality checked for run-out tolerances. Hi-Tech Roller Race Timing Set for Chevrolet 348, 409 COMP Cams Chevrolet 348, 409 Hi-Tech Race Roller Timing Set COMP Cams Hi-Tech Roller Timing Set CS