I had such a problem, Riley. Turned out to be a burned coil, such that when the coil was cool, the wires on the primary would be fine but when it got warm, they separated, broke contact and -no spark. When it cooled off the cycle repeated.
The fix was to throw the can-of-oil coil across the road into the woods (optional) and install a solid-state coil that was OEM from a newer Ford. It looks like a transformer. If thats it, you'll need to change your small coil wire ends from ring-connectors to male spade lugs. You don't need Ford's expensive molded plastic plug body.
A second possibility, if your car is a '71-72 with the early fuel tank, is a varnished fuel filter inside the tank where its not service-able. You reach in thru the fuel sender hole with a wooden (non-sparking) stick and RIP the cloth filter off the welded end of the fuel feed line..If you have a ;73-up, there's a fuel filter clipped on the end of the fuel line. To R & R it, remove the sender and snap it off. Autozone sells them for less than $5.