Classic/Antique Car Repair: Fuel issue, 57 chevy bel air, chevy bel air

Question
I have a 57 Chevy Bel-Air.  It was parked for sometime until recently.  Once I got in it and decided to take it for a spin I noticed I need gas.  I went to fill her up and it would only take a couple gallons.  It still was near empty.  I checked out the gauge and it seems to be operating.  I'm just not sure as to how to solve my problem.  Should I drain my tank ... blow out my lines...what do you think?

Answer
If I were doing this job I think that I would remove the fuel filler tube from the car first. This is attached to the fuel tank on a slip fit and bolted to the car body near the filler cap. Check the vent tube and the filler tube for obstructions. You can then stick a stick like a dip stick into the tank to measure how much fuel is in the tank. Be safe and do this only in a well ventilated space and remember that static electricity can cause the fuel to ignite. Be careful.
Brad