Regardless of whether your application is high performance street or all-out race, knowing that your accessory belt will stay in place at high rpm is extremely important. COMP Cams belt tensioners with idler pulleys fit all GM LS passenger car engines, including LS1, 2, 3, 6, and 7 and feature a higher pulley sidewall so that your serpentine belt always stays in place. The belt tensioners feature lightweight 6061-T6 aluminum billet construction and are black anodized to be attractive and functional additions to any LS passenger car engines. These COMP Cams belt tensioners with idler pulleys replace the stock LS engine unit but use the factory drive belt. Best of all, they are assembled and torqued at the factory for quick and easy installation. The new systems do not require disabling the stock tensioner and keep the correct tension on the belt, regardless of the demand. These components are not designed to work with LS truck engine applications.