The VMP 90mm idler pulley uses a factory size and an NSK brand, heavy-duty bearing, when the proper sized bearing is used the need for double bearings is removed. Use this idler to reduce belt slack and get better wrap with smaller supercharger pulleys. It can be used with 2.4", 2.5", 2.6", 2.7" or 2.8" super charger pulleys on a 07-12 Shelby GT500 and it can be used on the 11+ Ford 5.0L with the Roush, Whipple and VMP Superchargers as well. (Some filing may be needed due to core shift in the bracket for the idlers.) The VMP 90mm Idler Pulley can also used with Roush M90 and P51 TVS blowers. Keep in mind, when installing a smaller SC pulley, install below the supercharger pulley. Not only those uses listed previously, but it will fit other applications that require a idler with 17mm bore. The factory bolt is re-used.
On A GT500, the idler pulley should be installed the intercooler tubes, to the left side of the blower. The correct idler is highlighted in yellow below:
NOTES: Most pulleys require additional supporting parts. Contact MPT's Tech Support for addition information or questions.