Can't tell where you live in Texas, but when I lived in San Antonio it was easy to pull a tire and wheel off a junked truck at Pick and Pull, and they usually charged $25 if I pulled it myself. I always got it from another GM squarebody truck, just to make sure it fit and was the right width. Apparently Ford used the exact same 8 bolt pattern, but I'm not sure about width and offset.
Sometimes the junkyard tire is okay for a spare, but usually you have to swap it with one in better condition. Also take a close look at the wheel and tire for damage. I ended up with one wheel that had been damaged in a side collision, but didn't realize it until they tried to balance the new tire.
Bruce