I have a 9inch Ford differential with no history and in need of rear brake drums. The specs on it are: 11 inch inside diameter, 2.25 in. brake surface, 5 lugs on 4.5 inch, total height of drum is 3.25 inches and an axle opening of 2 & 7/16inch. I have searched with two different parts houses and researched online to no avail. The rear of the differential has a dimple on either side and the total width from inside backing plate to plate is 51 +/-inch. Evidently a early and mid size Ford but that is all I have. A friend of mine said he had one that size for a 1957-8 Ford but it seems that those drums are unobtainable. Help ????