A hydraulic pump or motor includes a mounting flange that is disposed at the first end of the housing. The mounting flange defines a pair of fastener receiving apertures that are disposed along the X-axis on either side of the shaft. The pair of fastener receiving apertures each define a radius center that are spaced away from each other a X dimension, and a pilot projection extends longitudinally away from the mounting flange, defining a pilot projection diameter. A ratio of the X dimension to the pilot projection diameter ranges from 1.07 to 1.11.