I have no experience with the 40 series, it has 1 fuel tank out in front of the radiator I emptied out the fuel tank and flushed with clean fuel put 5 gallons of clean fuel back in tank, now trying to bleed fuel filter.Then you have any number of possibles. So you don't know how/if it ran before all that took place, why it didn't run, what all was "messed with", or pretty much anything about the fuel system in general? Do you have any experience with Ford 40 series systems to start with, or are you basically working your way through?
I'm assuming it has an auxiliary fuel tank under the cab? If so, any idea where the fuel level is in either tank? If it's only got fuel in the lower tank, and it's only partly filled, then you will no doubt have trouble getting it bled, whether the hand primer works or not.
If that's the case, I have a few suggestions for you should you be interested.