Classic/Antique Car Repair: Fuel tank sending unit, 67 ford galaxie, fuel tank sending unit

Question
I just purchased a 67 Ford Galaxie. The fuel gauge was not responsive so I did some digging... The tank sending unit has two wires(1)ground (1)gauge. When shorted together the gauge indicates full. I replaced the sending unit and associated gauge 5 volt DC regulator (which does have 5V at output). There is no change in the gauge movement. It raises to just above "E". That is all it does. I have filled the tank ran it for days and filled it again...no change. The sending unit has about 83 ohms across it at last test. What do I do now?

Answer
A few questions. Was the new Sender new or used? Was it new old stock? Did it come with a new float?. Do you still have the old sender? When you check the old sender with an ohm meter in both the full and empty positions what does it read? Does the reading transition smoothly as the float is moved?
Brad