Ford F-250 stalling out

I would greatly appreciate advice for repairing my 2003 Ford F-250 V-10. After about 30 hours of almost non stop plowing in the last blizzard my truck started stalling out. I 've added dry gas, new spark plugs, air filter, mass airflow sensor, fuel filter, fuel pump and checked wires to pump, the truck is still stalling.
It seems to run fine for first half hour or so and then begins stalling out consistently, the truck also becomes harder to start after 1/2 hour but always starts.

Have a mechanic retrieve any possible fault codes
Get the fuel pressure system thoroughly tested
Get the battery and charging system tested
Have the mechanic check for parasitic draw
Replace the battery if it’s more than 5 years old
How’s the coolant temperature?
You haven’t overheated the engine with all that plowing, have you?
It sounds like it’s time for fresh coolant and a temperature, based on the age of the truck.
It also sounds like it’s time to do a trans fluid and filter service, based on the age of the truck.

Thanks for the advice. Will change fluids as you suggest and have a mechanic check for parasitic draw (what exactly is parasitic draw?)

The dash is not showing and codes, I had the truck at a shop for diagnostics, told it was a bad fuel pump. I replaced the pump and still stalled out. I then brought the truck to a ford dealer, I was told it was corroded lines to pump, they repaired the lines and sent me on my way, shortly thereafter I stalled out. Battery and charging system checked out ok and I have a new battery in the truck. Coolant temp is ok and the truck never overheated.

Parasitic draw is unwanted electrical “usage” with the ignition off. A dome light left on would be an obvious example of parasitic draw.

One thing to check for is a defective crankshaft position sensor. These sensors can fail once they heat up causing the engine to stall. Then once the sensor cools back down the engine starts and runs

Tester

My Ford Truck sometimes develops this symptom, and for me it has always been a vacuum leak. The symptoms would be that it worked perfectly for months and months, then one morning I would turn it on and it would idle rough and stall out. It was like Jekyl and Hyde.

A vacuum leak can be caused by either a leaking hose or a leaking vacuum controlled device. You have to check for both. On my particular Ford truck, the most common cause was a leaky device, the gadget in the air cleaner which allowed heated air from the exhaust heat riser into the intake manifold when the engine was cold. That would spring a leak from time to time. Replacing it fixed the rough idle and stalling problem straight away.