Don't think that's accurate. The bolt is #1448 and the "nut" is 1474. According to our page at Documentation/Exterior/Spare Tire Carriers there's no such thing as an F250-only either of those. Lots of F250/350, and many F150/250, but no F250 that I can find. And, it is a very complex area.
I've sent him a note via eBay.
Gary, AKA "Gary fellow":
Profile
Dad's: '81 F150 Ranger XLT 4x4: Down for restomod: Full-roller "stroked 351M" w/Trick Flow heads & intake, EEC-V SEFI/E4OD/3.50 gears w/Kevlar clutches
Blue: 2015 F150 Platinum 4x4 SuperCrew wearing Blue Jeans & sporting a 3.5L EB & Max Tow
Big Blue: 1985 F250HD 4x4: 460/ZF5/3.55's, D60 w/Ox locker & 10.25 Sterling/Trutrac, Blue Top & Borgeson, & EEC-V MAF/SEFI