The Pantera sender is a zero to 200 ohm sender according to Bill Taylor's wiring diagram. If you install a 40 ohm resistor in series between the gage & sender "empty" on the gage will agree with empty at the sender (240 ohms), full will be 40 ohms instead of 33 ohms, so the gage will read about 1/2 gallon low when the tank is full (3 1/2% error).
cowboy from hell