#1. Gas would not necessarily flow from the line at the fuel pump, especially if you only have 3 gal. of gas in the tank. The Birds have a tendancy to sit low in the rear, so it is very possible the level in the tank is below your fuel line at the pump. I believe there is a filter sock, inside your tank, on the fuel line. If the car has been sitting, it is very possible this filter is plugged with rust etc. You may be able to blow air through it, but the fuel pump may not be strong enough to pull fuel through it. I hope you are removing the gas cap if you blow air back through the line. It doesn't take much pressure to distort a tank.
The fuel pump is designed to pull a small amount of vacuum to pull fuel from the tank and then controls the discharge pressure of the pump by using spring pressure.
I believe that the connection for the fuel pump, even though it is at the bottom of the tank, has an internal pipe going to the top of the tank, to prevent a major fuel leak if the flex line goes bad. This is probably why they also put a second drain connection on the tank, and the reason why would you would not have gas flowing in the line at the pump.
BTW, it is not at all uncommon for the old Autolite carbs to loose fuel after sitting for a few days. I fought mine for several weeks, until I finally got it to hold fuel in the float bowls. I can now go for weeks and it fires right up. ;-)
If you have a vacuum guage, you may want to hook it up to the fuel pump and see if the pump is withing specs. It should pull a small vacuum when you crank the car.