Is my gas tank full?

I tried on the 2nd gen forum, got nowhere, now i'm here looking for better luck with constructive replies, this is really bothering me. Thanks for looking.

Problem is you need gas to make the dang truck run.
Here's my problem.
Truck would start and die, start and die, I know its out of gas. I put approx 2 gallons ish in. Drive to gas station. Can only squeeze 7 more gallons in. My math makes that 9ish gallons, WHY?
Gas gauge reading correct is another issue.

 

Dented fuel tank causing fuel pump and capacity issues?

 

tank is perfect on the outside

 

its just like i said, would start n die, start n die. i put 2 gallons in runs perfect.

 

Years ago I had a Dakota that convinced me the fuel pump was bad. But the symptoms depended on how full the tank was. After buying a pump and pulling the tank, I figured out the rubber fuel line inside the tank had split. So whenever the fuel pump ran, it sprayed fuel back into the tank. When the tank was full enough to submerge the leak, it added some resistance, and slowed the leak, and truck would run. When the tank was low, it leaked enough to keep it from running.

I'd imagine the odds are slim this is your problem, but its a possibility.