I hate to derail, but do you have a F150 Powerstroke or a F250? If the F150, then continue with purchase.

If the F250, you can absolutely not use these tires due to too light of a load rating.

You can still get the road hazard warranties at Discount Tire. I've done it before. As long as they look new and you didn't buy them from a competitor, DT will still sell you the road hazard warranty.

Similar to this situation, I bought a set of tires from a guy off Facebook that had less than 100 miles on them, then I went to DT and paid them a nominal fee of like $20 per tire for them to mount and balance them. I asked if I could get the road hazard warranty for them and the Discount guy said where did you buy them? I said I got them from a guy off Facebook and he said yes as long as you didn't buy them from a competitor like NTB, Tire Rack, etc, they will still sell you the warranties.

You can do the same thing with new tires on a brand new vehicle you just bought. Obviously you didn't buy those tires from DT since they came with the vehicle brand new, but as long as it has like 500 miles or less you can still go to DT and get warranties for them.