I got past this issue but still looking for what the real problem was....
My '49 1/2 ton had the original engine which I converted to 12 volt (starter and generator), eliminated the points (Pertonix), new fuel pump, carb, water pump, etc. In other words all the outer gear. It started right up and ran fine but after about 5 mins it would seem to run out of gas. I checked the obvious stuff, debris in the lines, filter but that all checked out. After lots of unsuccessful troubleshooting I got another new carb and later another new fuel pump but still same problem. I found an old timer, I'm 69 so if I call him an old timer, you get the picture. He "fixed" it by suggesting I put an electric fuel pump inline between the gas tank and the mechanical fuel pump, like a helper. His theory is that today's gas is "weaker" and at least partially vaporizes once the engine warms up so it starts demanding more fuel than the mechanical pump delivers. I'm not sold and couldn't find anything about that here on Stovebolt or anywhere so, if everyone is doing this or something else to address it then it's a very well kept secret.
I am now running a small block but still very much want to know.... Is the gas really the problem? and if not then what's wrong that an electric fuel pump fixes?
I'm sure it can happen and with my luck it would happen to me, but two new fuel pumps that were both working but possibly both weak with identical symptoms? That seems far fetched.
BTW.... Me and my truck want to thank everyone here for all the great info, and I never even once had to ask cause all the answers were already asked, answered and waiting.
