[leftybass209]

Next would be to change all the fluids and filters along with a new thermostat and radiator flush and again let it run. Right?
If it fires, then you can worry about draining fluids and changing filters and flushing the radiator. As it sits, the oil should have enough viscosity to run for 5 minutes or so, but I'd drain a bit out of the pan to make sure you don't have water in your oil. In that same 5 minute time frame, the coolant shouldn't get warm enough to open the thermostat, so you don't have to go through the hassle of changing it before you know it will run continuously.
And replace any lines that may be cracked or leaking.
This should be done after you know it will run continuously, but before you go replacing fluids and getting them contaminated with whatever junk is in the lines, hoses, and filters. I'm sure you knew that already, it was just worded out of order.

Over all I would assume your goal is to ensure the truck runs without wasting money on extra filters, oil, coolant, and lines. With that in mind, always remember to replace everything between point A and B that might contaminate your new fluids.