Vapor lock issue
 

Long story short... I was unaware I was having a vapor lock issue in my 7.4mpi until I recently worked on two 502s. They did not have the "cool fuel" set up an the issue was narrowed down to heat being the culprit to starting after engine was hot.

After two days on the water tubing an the like I had my 7.4 vapor lock on me two times. I did some reading and found a few fixes. Can't say how I'll remedy my issue yet but I have some ideas now. I was bleeding off some hot fuel/vapors at the fuel rail Schrader valve an had luck.
I'm going to attribute my issue to a well insulated engine compartment.

https://www.perfprotech.com/blog/art...ser-vapor-lock

Apparently there was a TSB for this issue.