The drop box reduction housing is used in place of the stock reduction housing. This housing lowers your driveshaft height by about 7" from stock. To be used to make your own low rider like our "Half Pint" tractors. Can still use the internal brake. Front reduction gears are a 55T big gear against a stock 12T gear (from your reduction housing). Other big gear ratios are 10/57, 11/56, 13/54, 14/53 and 15/52. Two versions are available-- one is for the 1 cylinder K-series engine (driveshaft is offset to the left 1/2") and one for the V-twin which pinion is in the center of the drop box. Uses stock front pinion bearing and seal.