Ok, got some updates on this.
I have been driving it to work for the past 2 days almost without issue, some power loss but otherwise ok, and I'm clocking about 275 miles so far without running out of gas.
Now, the bad. I left my wallet at work today and had to go back to work to get it, almost right after I got home, it has only been about ten minutes since I shut the truck off. Well, it was extremely hard to start, I had to keep my foot on the gas pedal until the idle smoothed out and it stayed running.
After that, it drove like complete shit. All the way there and back I was at almost a complete power loss going uphill, literally I could stomp the gas and wouldn't even hold my current speed (about 68 mph). So I got it home, scanned for codes, no codes, and looked underneath, and my catalytic converter was glowing red. Maybe it's trash??
Now, when I bought the truck, I was told the heads had been redone, by the PO and his father, who worked at the local Ford dealership as a Mechanic, so I though I was good. Now, if they didn't set the timing right, like, if they set it 180* backwards, could this also make the CAT glow? I have no real way to check the timing as I don't have a timing light (nor the know-how to use one), but is this a possibility?