My brother has a 64 Econoline PU with a 144 and is having issues with it. It will run fine and then all of a sudden start sputtering and quit. There is no rhyme or reason with how or when it acts up. It will run fine for several Days and then wont run at all for more than a few miles. After it quits and we get it drug home it sometimes will start back up and idle for long periods of time with no issues and other times it won't run at all. We have pulled and cleaned the tank, made sure the vent is clear, replaced all the lines, installed new filters, he is on his 3rd fuel pump, all manuel. He is sure it is fuel related but we are stumped. Anyone have any ideas...........Kid

I had one that was doing similar stuff.
Ended up borrowing a carb and swapped them out, problem went away.

3rd fuel pump solved the problem

Kid, try a different coil if you haven't already done so. I've had them fail when they warm up. Then start & run after they cool down. good Luck! Never mind, just read your last post.
Not real keen in my old age! Although running three fuel pumps may cause flooding!! Just kidding HA HA!!

Gas filter.