definitely a 58, the vin will be xx58xxxx .... I doubt it'd fit on a conventional cab frame without some major work, but for frame comparisons, check the 58 resto-pack
"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