yes, that drawing isn't very clear at all, maybe they hadn't quite figured it out yet I recall my 57 stepside brace rods attaching to the cross sills [front or back face], and the fleetside does that too
"When we tug a single thing in nature, we find it attached to the rest of the world" ~ John Muir "When we tug a single thing on an old truck, we find it falls off" ~ me Some TF series details & TF heater pics