Should be easy enough to rule out a couple of things:

Evaporation : Start up the car and shut off immediately before anything gets warmed up. let it sit for a few days. If it starts right up then it must be evaporating dry when hot.

If it doesn't start, somehow try to block the fuel from draining back. There are 2 rubber check valves in the fuel pump (I'll see if I can find a pic) if they have degraded/cracked due to ethanol gas (or being 40+ yrs old) they would still allow the pump to work but would not stop the gas from slowly draining back. Its basic physics as the quadrajet carb level is above the gas tank level. If the carb float is low and needle is open in the carb seat, then you need the fuel pump check valves to hold the gas from draining back. (or a one way check valve type fuel filter as Wade suggested above)

If you have a rubber fuel line anywhere in the system, try using a vise grip to lightly pinch it off & try in a few days. If you don't have any rubber then I suppose you could undo the line from the tank at the fuel pump, plug off to the tank and monitor if its slowly dripping backwards out of the fuel pump.

It could also be the wells that were epoxied are still leaking depending on how it was done. You'd have to pull the carb off to rule out that one.

These are a few things you could try, as always be very careful with gasoline & taking apart fuel lines. We tend to forget how flammable & dangerous gas really is. My little disclaimer LOL !!