I have a 1999 Ford F-350 dully with the V-10. Truck has 135k miles on it. Truck has a few things going on. 1st is it won't always start the 1st time you crank it normally starts on 2nd try. 2nd issue is it runs rough at take off like its running out of gas then it takes off and runs fine. 3rd when it runs rough sometimes it feels like the break is on or trans is holding it back a little. 4th sometime it shifts hard and runs rough but if i shut it off and restart it runs and shifts fine. and lastly if i turn on the a/c or head lights it runs rough like its running out of gas and it goes away as soon as i shut them off. Fuel pressure at rail under load is around 40psi, just changed fuel filter, and have ran seafoam and a few tanks of gas through it.

 

Just some shots in the dark ideas...
- Before you start it in the morning, try turning the key to the ON position, listen for the fuel pump to buzz on and let it prime the system. It should turn off after a few seconds. Turn key off, do it again. Finally, crank motor...did the truck start first time?
- Double check any vacuum hoses (mainly the PCV hose) from passenger side valve cover up to intake. (Worth checking all hoses and small red vacuum lines). Also check the main intake tube for any cracks (especially around the convolutions/ribbed zone).
- Noting that when the headlights are turned on that notice a loss in power, I'd break out a multimeter and see if there is a significant voltage drop. Idle voltage should be at or around 14V. With any accessories running at idle, should be 13.5 to 14V. This could point to a faulty alternator but also could be dirty connections (check all grounds from engine to chassis and body),. Check positive connections for corrosion.

It seems to me at least, that most starting issues or non-start issues end up being a failing/faulty fuel pump for these trucks... so you might want to check the fuel rail pressure before starting, during cranking, at idle, etc.