Classic/Antique Car Repair: where is my fuel going?, glass filter, line thanks

Question
I have a 56 T-Bird with the 312 engine,when the car sits over night the fuel filter is at most half full& the carb. is dry: I have a rebuilt carb,a re-built fuel pump,a re-built brake booster.The fuel filter is in line to the carb.I made sure the glass filter bowl has a good seal as well as all gas lines.Is air getting in to evaporate the fuel ? or is the gas draining back to the tank ? if fuel is draining back to the tank can I put in some sort of check valve in the fuel line ?
Thanks for any help
Lou

Answer
Are you having a problem with the car?
Or? Are you making one?
Does the car start and drive ok?
Then don't bother with little things like this...Is your gars filter higher up  on the engine?
Then the gas is draining back into the lines... which is TOTALLY normal. When you pump the gas in the morning it will fill right up again.
Adding a "check valve" does nothing to make your car run better. It is just one more thing to go wrong.

If there is a real problem  let me know and I will help you...if the car runs well.. enjoy it good luck