This 8-Rib Belt Drive Conversion Kit is for use with E-Force equipped 2013-2019 5.0L Mustangs. It enables the use of a wider, 8-Rib supercharger pulley instead of the standard 6-Rib design. The 8-Rib belt drive will allow customers to substantially increase boost levels by installing smaller 8-Rib supercharger pulleys. The larger belt contact area on the wider pulley will help eliminate belt slip prone to small-pulley, 6-Rib configurations. For use with 2.625" to 3.75" pulleys.