Not true with the stock return-line style fuel pumps...
There is a small orifice about .058" in diameter in the pressure side of the fuel pump which allows pressurized fuel to return to the tank to prevent vapor lock. When sitting overnight or longer, once evaporation of fuel in the fuel bowl is enough to allow the float to pull the needle out of its seat, some fuel will back-flow to the tank through the needle and seat assembly, the filter to the pump and then through this orifice into the return line to the tank. If the needle and seat assembly has side windows, the level of fuel can drop lower. When fuel drops lower than the spill way notch into the accelerator pump well, the accelerator pump runs dry.

Solutions:
1. Leave off the float clip to the needle so it won't be pulled up allowing fuel to back-flow.
2. Use a needle and seat assembly without the side windows so that fuel can't go lower than the top of the brass seat assembly, thus affording a higher fuel level to replenish the accelerator pump well.
3. Have a check valve in the filter or carb fuel line.
4. Without a check valve or solutions 1 or 2, crank the engine for a count of 4 before expecting it to start.

 

If it's a stock 78 carb it should have the long filter.

Jumping off of larrywalk's post, are you sure the needle seat clip is attached correctly to the float arm? It should be attached to the bump on the rear of the arm, not in either of the holes on the arm (or not attached at all)

 

Or, it can be left out, altogether. It's better to leave it out than to install it incorrectly.

 

I have had the same problem. I can only imagine that the heat from a hot engine (after it is shut down) will cause the fuel in the carb to evaporate away. I epoxied my well plugs several times myself and paid a pro to do it twice. The carb is still empty after a little while. Bench tested it, found no leaks.

 

Thank for clearing up my misinformation about the fuel pump check valve and thanks for a good explanation about drain back.
We have been all over the map with suggestions, lonzoo thought the well plugs were leaking and there not.
Could it be that he just needs to set the choke properly?
One pump of my gas pedal and it starts in 5 or 6 seconds even if not used for a week.

 

Yep; just the choke and it should start in 4 seconds - no pumping required!

 

Yep, hence the "or not attached at all".

Attaching the clip does help prevent the needle from getting stuck in the seat after long periods of sitting, though.

 

UPDATE: Since replacing the filter the car has started flawlessly for 3 days after sitting for 24 hours. Keepin my fingers crossed cause I just don't trust these type filters. Still looking to install a seperate fuel check valve in the line and remove the paper filter. Thanks again guys ..you have been a big help.

 

There is nothing wrong with the little paper filters and [internal] 'flapper' check valve...if you install the correct part. There are different lengths and it seemed as if the first one you installed was too long.