Help with my 83 d150 slant six. Issue while driving and dies in the middle of the roa

Any help would be great.

I have a 1983 d150 slant six 1bbl and I'm having an issue when I'm driving the truck out and the ambient temprature is hot it dies on me. I have to hit the gas all the way to the floor for it to start. Sometimes it will start with one go and sometimes it wont. I've noticed this more now since it's hot out, because when it was colder out I didn't have the issue. What could cause this? The fule filter looks clean and clear I changed the fuel pump on the block. Could it be a bad sending unit? Dirty gas tank. Any help would be great
Author: Slantsix