The likelihood that someone converted an open drive shaft truck to a torque tube setup is extremely remote. The fact that the truck has a torque tube almost certainly means that it cam that way from the factory.
Bill Hanlon's TSB indicates that most trucks in '54 had torque tubes.
Posting the door tag information will enable confirmation of this.
1950 Chevrolet 3100 (Ol' Roy)
1939 Packard Standard Eight Coupe (The Phantom) | 1956 Cadillac Coupe de Ville (The Bismarck) | 1964 Ford Galaxie 500 coupe |1966 Ford Mustang (Little Red) | 1969 Pontiac GTO (The Dishpit) I 1979 Ford F-100 | 1976 Ford F-150 (Big Red) | 1995 Ford F-150 (Newt)
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