Fuel tank sending unit
I bought a brand new tank and new sender from an aftermarket company last year and my first problem was the sending unit wouldn't seal tightly and leaked so I had to use my old original gasket and lock ring to get a good seal. Second problem is the false fuel level reading, I think I'm about 5 gallons off, it shows empty with fuel still in the tank.
Over the winter I've developed a slow leak in the fuel filler neck gasket, hopefully with warmer weather that will fix itself???