How about these. Truck takes one, I have two. One is stamped "N" like the rag joint bolts. The other is stamped "WB".
Trivia, the "N" bolts on at least my ride were special bolts, for lack of a better term. Rag joint, bed to frame carriage bolts and this.
Double F were special bolts too, you know, like the one you guys haven't figured out yet post 138?