Vortech mounts its blower using this plate assembly. The rear plate facing the camera is steel, the front plate is aluminum. Vortech is shipping this as an assembly pretty much as shown here, complete with idler pulleys and belt already wrapped in place. With all pulleys mounted in double shear, this should prove a rigid, long-lived piece. The row of holes at 4 o'clock allow repositioning an idler gear to accommodate different blower drive pulley sizes.