Can only share my personal experience. Stock 273 2bbl NO carb spacer, aftermarket stock mechanical fuel pump. If the car was driven yesterday 2 pumps and it will start on the first or second crank attempt and stay idling and drive no problem if it has been a week 2 shots, 2 crank attempts 2 shots and 1 or 2 more crank attempts and it will stay idling and drive no problem I have verified both ways that there is fuel in the accelerator shots both 2 shots and 4 shots worth. Fuel pump was last changed 2011 (100,000 miles ago) OEM fuel pump ran 163,000 miles I suspect that either the "it won't start crowd" are waiting months between starts, have a mechanical issue like a pinhole leak, check ball leak, or are so used to EFI that multiple crank attempts seems bad. Or maybe flooding it with too many pumps or too open a throttle or too closed a throttle or no choke or too much choke. Older ford 2 and 4 bbls had open vents to the fuel bowels (IIRC) and did not have evaporation issues. Yes fuel was different BUT if you are loosing 10% of the alcohol to evaporation you still have 90% of the bowl full. 2 inch tall bowl would be only 1/4 inch low and with only a few cranks it would be full unless the pump is sucking air. if you want to know for sure if it is evaporation, take a cup of fuel from your tank put in into an aluminum can and put it on top of your hot engines intake manifold after you shut it down. the next day see how far the level has dropped in the can. then you have PROOF that it is evaporation and not a leak. USE OBVIOUS SAFETY PRECAUTIONS WITH THIS TEST! These are my findings and opinion yours will be different, flame away if you want.