If you have a local junkyard near you, the bolt is the same as the bolts on 95-01 explorers and right now, those are very plentiful in the yards thanks to Cash4Clunkers. Might give that a cheap, free in your pocket shot.
The bolt I believe is M12-1.25x?? IDK the length. I want to say it's between 80mm and 90mm. You can use a standard grade 10.9 metric bolt if you wanted, but make sure it's fully threaded. A regular bolt would have a 19mm or 18mm head...so that might be a little tight up in the hole. Or, as said above, hit up the Ford dealer for an OEM replacement.
'01 XLT disguised as a '03 Fx4 Level II.