Why isn’t fuel going to the carb?

Not to get textbook, but you should tee in a fuel pressure tester. (excuse this if you already know this) When the tank is dry, or the car is out of gas, it loses prime, you can drain the battery cranking it until it regains prime again. (By prime, I mean the fuel lines are full of gas all the way up to the fuel bowl, think of it as air in the system like bleeding brakes) What I do to re prime a carbureted car that is out of gas is, I make sure there is gas in the tank, then drip a small amount in the carb, enough to fire the engine. the engine running at RPM makes the fuel pump work alot better than cranking. If you are sure there is gas in the tank, fire the engine over a couple of times untill the lines prime up.