ALL NAPCO conversions in 1955/56 were done by the dealer or owner with parts bought from a local NAPCO dealer, there were no "factory" installed units...your truck was born as a 2-wheel drive truck.
Mike B
Mike Boteler
1956 Chevy 3100 Resto Rod 1952 Willys M38 Army Jeep 1983 Jeep CJ7 Laredo 1984 Jeep CJ7 +++++ Silver Spring, MD