Calling all old schoolers.......

We had a ‘90 F700 with a 429 gas burner that did the same thing and it was the ignition module. It would get hot and wig out. After it would sit and cool down it would work for a while till it got too hot again. We carried and extra one in the truck after we figured it and replaced it.
We worked the crud outta that truck. 26,000 gvw with a 22 ft box got loaded beyond that regularly so that engine was hot all the time.

 

Check the ignition module, just for giggles.
They get hot, then shut down until they cool a bit, then start up and run fine for a while.
Had similar problems with Ford and Dodge vehicles.
The Dodge was cheap, carried a spare, Ford was pricy, couldn't afford a spare.

 

....plugged fuel return line? Do a sniff test.

 

The pick up coil or stator in the distributor will break down when it gets hot too.

 

I’d guess rusty fuel tank, plugging filter. Maybe a see through filter near carb, for starters.

 

Rebuilt the fuel pump?
Should be located in the fuel tank and it should be a factory sealed non rebuildable electric pump?
I have seen where you can’t get the whole assembly with the the sending unit and pump already assembled?
Did they just get a new pump and install it in your sending unit assembly?

 

Great
Hope your road test goes well.
Your going to love Mt Rushmore it’s an awesome place to visit.
The evening lighting ceremony when they call up and honor all the military veterans is especially nice.
You should also check out The Crazy Horse memorial while your there.
And I also recommend a trip to Devils Tower in Wyoming only a short trip away if you have time.
When I went out with my fifth wheel camper we stayed at the KOA in Rapid City.
Great nice clean camp ground.
I highly recommend it.