Hey JTex, welcome to classicbroncos!
So just prior to cleaning the tank and putting in a new line it was not running for 15 years or so? Or you had it running fine, then just fiddled with the tank and lines?
And what did you do to clean the filter and pump? I would say that at this point you should replace the filter. It's only a few bucks and minutes work, so well worth it in the long-term.
Although cleaning is a long held way to deal with those old style filters, it's not perfect.
Of course, you could verify that your ignition is in top shape, and the engine has had a full tune-up first, but you might just get away with a slight adjustment of the carburetor at this point.
Two things can cause it to die like you're describing (well, probably 38 things, but we'll start with the two most common?). One is that the idle speed is simply set too low because when the choke butterfly comes full open the high-idle linkage is released. Perhaps before this it was sticking on it's last notch and the idle speed screw was adjusted to compensate.
The other thing that's common with older engines is vacuum leaks. VERY COMMON in fact!
Too much air will kill it pretty surely, and closing off the choke plate/butterfly/thingy will richen up the mixture enough to let it run again.
So a few things to deal with right off. You and your dad should have lots of fun piddling around on it. Even during the frustrating times.
Haven't heard that word in a long time. Piddling was one of my dad's favorite terms I think. He was from West Virginia, via Kentucky and Ohio, so not too far from your current stomping grounds. Might be a common thread with words.
Oh, and one more common thread with these fuel issues after sitting, is that the fuel pumps just up 'n die not long after the first few starts. So no, you have no guarantee of getting reliable fuel to the carb just yet.
Yes, you could get lucky and your pump will live long and prosper. But more often than not these days they die quickly after having sat so long.
So it's one more thing to keep an eye on while you're working on the project.
If things start to seem a little off, keep checking the oil level and smell to make sure the pump diaphragm has not ruptured and pumps gas into the crankcase more efficiently than it does to the carb.
Good luck.
Paul