It used to be very common on quadrabogs to drain the carb back into the tank. They solved it by adding a rubber check on the fuel filter.

There are 2 check valves in the stock fuel pump, the first lets fuel into the pump chamber and as the diaphragm pushes down the first valve closes and the second valve lifts and allows the fuel to exit the pump going to the carb. It is possible that these valves are damaged and allowing the fuel to drain. But if the carb is full in the morning as evidenced by looking into the throat and pumping the accelerator lever and seeing fuel sprayed into the carb then that rules out the pump valves.

Also my memory tells me the the fuel filter on that ford is high enough to prevent the carb from going dry.. but don't forget I CRS... (can't remember S _ _ _)