Cast iron; 2.280 in. Diameter filler neck hole; 0.486 in. Diameter gage rod hole; 0.500-14 npt internal thd holes on one side of housing; rectangular mtg flange 4.500 in. W; 7.125 in. Lg w/four 0.410 in. Diameter mtg holes spaced 3.750 in. C to c along width and 6.188 in. C to c along lg