I had the same problem on a 454 Chevy in my truck; it would run as long as I had gas in the carburetor then it would die. I put a new pump on it, same thing I even put gas in the line to prime it. I went on to other projects and thought it must be rust in the tank that stopped the flow.

Now I have the same problem in a 302 Ford engine in a 54 Merc that was sitting for along time so I thought it must have had rust in the tank. This time I did the gas container sitting higher then the engine with a long rubber gas line to the pump, still no gas coming through. I'm going to get a new pump this morning and hope that solves that problem.

Richard