1953 Ford Customline dies after it gets hot.

[JIMBOSCHIZEL]

Hello
New member glad to be here.
My name is Jim.
I am writing this for my father.
My father has a 1953 ford customline with the 239 ci flathead.
This 53 was given to my dad from his brother completely restored to factory 20 years ago.
My dad takes it to multiple car shows in south Washington state when the the weather allows, this car drives to each show. She is no trailer queen.
He has been having a stall issue when the motor gets hot (not over heating).
Carb, wires, cap, points and now a Pertronix electronic pointless module, has been changed.
Vacuum hoses and plugs have been replaced.
Engine comp is 95+-2psi all around.
The car does have a electric assisted fuel pump that is switch activated.
We have not adjusted valve lash.

My dad has 50+ years car experience and it has us dumb founded.

We would appreciate some incite or ideas into diagnosing this or has anyone had this happen to their flathead car?
Thank you