C/o a tube 18.500 in. Lg, with a 6.500 in. Sq flange welded on one end having four mounting holes, id 4.405 in. Min to 4.465 in. Max to a depth of 4.750 in. On flanged end, id 4.435 in. Min to 4.440 in. Max to a depth of 13.750 in. In end opposite flange, flange 0.750 in. Thick