Quick view VMP Performance VMP Performance 2020+ Shelby Ford Shelby GT500 5.2L 20 Percent Overdrive 8-Rib Balancer Kit - VMP-20OD52KIT Compare $1,499.99 The mid-level 20% OD kit adds 3-4 pounds of boost and includes the parts necessary to complete the installation.? Includes the required VMP heavy duty belt tensioner with 58MM idler pulley to clear the larger diameter balancer ring.??This Part... Add to Cart Add to Cart