I have a 79 Scout stock everything, 345,4x4, 4speed. Replaced the fuel tank with a used tank (completely refurbished), new vent lines, new sending unit (SSS). Fuel gauge does not give accurate reading, I'm guessing at full tank the gauge is reading between 1/2 to 3/4. Is there an adjustment to get the sending unit and the gauge in sync ? Where did I go wrong with the installation ? The Scout had a 33 gal tank that I replaced with the stock 19 gal, Would the gauge somehow be adjusted for the 33 gal tank ?