Another possible cause is the needle sticking in the carb. Try this the next time it happens: Tap the carb near the inlet fitting with the plastic handle of a screwdriver. Sometimes this will unstick a binding needle and allow the carb to refill.
Still no fuel? Remove the fuel line from the carb fitting, using a short length of rubber fuel hose connect it to a fuel safe conainer, an old water bottle works well. Crank the engine with the key off, if fuel will flow then, then the needle may still be stuck. Should be able to supply a half a cup in about 15 seconds of cranking. No fuel, maybe the fuel pump itself is defective, or it's vapro locked on the supply side of the pump.
A length of clear hose, (vinyl works well), spliced into the fuel pump inlet, between it and the supply line will show if the fuel pump is pulling air or vapor into the inlet. Air bubbles in the stream of fuel on the supply side indicates a pinhole in a fitting or hose. Pure air, it may be vapor locking on the supply to the pump side. Solid fuel supply to the pump, but it still doesn't work may mean sticky or inop check valve.
Inspect the supply tube that goes behind the timing cover, it is normally mounted with two "P" clamps with insulation between the "P" clamp and the tube. If it is solidly mounted with a metal clip, and/or it's rubbing on the block, it may be picking up heat directly from the engine.
Hope this helps!
43 Ford GPW 92098
53 Dunbar Kapple M100
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USMC Tanker (1811, 1812), 85-93
ASE Automotive Master tech, former Chrysler-Jeep Level 4 Mastertech, CA state EA smog license