Worst that can happen is you push some crap in to the carb then it will need to be cleaned. If your confident in the fuel go for it, it should be fine. How long has the truck been sitting for? Have you gone through the carb?

Another thing you could do temporarily is disconnect the fuel line at the carb and slide the fitting back far enough on the line to get a piece of fuel line on it then install a barbed fitting in to the carb and use a loop of fuel line and a filter there.