I guess not heat soak or vapor lock. Maybe a gunked fuel tank and your new filter is getting clogged again?
Points or elec. ignition?
My Bronco had a similar issue and it turned out to be dirty electrical connectors going to ignition wire (it has a bullet type). I think your smay be the bulkhead. I am always nervous pulling these apart, but it may hav corrosion. A cleaning and then some dielectric lube may help.

Sorry, with my limited experience that is all I have to offer. If it feels the same as before and wires/fuel filter fixed it, that is a good start.

Good luck.