Forman, since your post is now almost 12 hours old I'm guessing the question is moot with the truck being unloaded. But if not, by now the gasoline will have evaporated and the (very real) danger of accidental ignition has passed. If I'd been in your shoes and needed to crank the truck with the gas wet conditions you described I "would not"....until after washing the whole area with water and then waiting until things dried to the point all danger of a catastrophic fire had passed. With gasoline leaks (natural gas and propane as well) Always err on the side of safety.
"Did air pressure suck the fuel through the pump?" Well, something happened. Hard to imagine negative pressure pulling fuel past the needle and seat in the carb unless the float was stuck in the down position. With a open fuel line at the carb, perhaps.
Good Luck!
RonR
Last edited by moparguy; 10/08/2019 10:39 AM.