Well first of all a Super 77 should have 2 fuel filters, a small one by the oil filter(s) and a larger sealed unit by the injection pump. If you only have one filter and it is by the dipstick you have a filter set up for a Fleetline 77 tractor. On the Roosa Master pump  for a Super 77, less than 100 tractors were built that way. Questions:Post a serial number.