I'd say 58/9 too - aside from the 8/9 fleetbed, the hood hinge mounting point is slightly different on the cab firewall, and not easy to make the 58/9 front sheet metal mount to the 55/7 firewall - numbers should tell ya what year
kinda crude steering col install - might be worth gettin if ya want the front frame clipped, and it's cheep enuff
Bill