Fuel issue

[REDROCKER652002]

Howdy all, my son ran into another issue that I am going to post to get some opinions on. His truck is a 1969 C10 with a 305 engine and a 4 barrel carb. The other day, he stalled out driving around the house. He was able to get the truck started again, but I guess it stalled out again. He was able to get off the road and we had it towed home. It kicks over, and when I put gas into the carb it will run, but will die once that gas is used up. He bought a new fuel pump, he works at a auto parts store so it was a cheap part to try. That did not work. He disconnected the lines at the fuel pump and said he is getting gas to the inlet and outlet, but once he connected the line to the carb the fuel is not getting to the carb. I ask him, and he swears there is gas in the tank. My question, and I have had to work so I have not really had a chance to look yet, what could cause the gas to go thru the pump, but not get up the line to the carb? He took the line off the carb and blew air thru it and said it was not plugged. It is a standard fuel pump, not electronic, and the gas tank is still in back of the seat.

I am more just looking for suggestions because I have been working and he is doing this on his own. I think he may be out of gas and does not want to tell me, but if he is getting gas thru the pump that would tell me there is gas in the tank. Any suggestions on where I should start?

Thanks in advance

RR