vapor lock question

[wyatt earp]

I have a 86 3/4 chevy 350 v8. It has a quadjet carb. Last week after driving to pick up hay ten gong to haul 55 gallons of water to my horses and back again for more water, my truck deciding not to start after all that was done. Called my wife and she cam and picked me up. I let the truck sit over night. Went out the next morning aand checked for spark o the coi. It was not a ble spark bu more of an orange and kinda weak. So I had my wife get in and try to start the truck again. This time i added a little gas in the crb and it started right up.
So i was thinkng more of a vapor lock. Then just yesterday it did it again but this time driving down the road. I got my hay, and water and was just leaving the water station and it sputterd and died. It would not start, so i waited a few mins. and tried again it started right up and never did it again.

I have changed the fuel filter, but just in case got a new fuel filter, a new coil and a fuel pump yesterday. Have not changed aything just yet.

I really don'tmess with the carbs that much so not sure what could be causing it to sputter and act like it is not getting any gas, or maybe just gets an air bubble in there.

Now i got a pm last night about how to look for something, jut wondering what everyone else might think this problem would be. This truck is my main transportation to get feed and water to my horses so it needs to run.