You basically have diagnosed your own problem. Start by pulling the gas tank and cleaning it or replacing it with a reproduction. Rock Auto has fair prices on replacement tanks. After that issue is resolved, replace the rubber and steel gas line from the tank to the pump and from pump to carburetor. Change/add filters along the way. No sense fighting old stuff when replacing is reasonably cheap. We can only assume you are referring to your ‘53 3/4 ton.

Martin
'62 Chevy C-10 Stepside Shortbed (Restomod in progress)
'47 Chevy 3100 5 Window (long term project)
‘65 Chevy Biscayne (Emily)
‘39 Dodge Business Coupe (Clarence)
“I fought the law and the law won" now I are a retired one!
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USAF 1965-1969 Weather Observation Tech (I got paid to look at the clouds)