1956 Ford, full custom that I built in 1975. Had a 390/c6 combination out of a Mercury Monterey in it.
There were lots of hot rod pickups in the 50's and 60's. F100's were popular from the beginning and the 28-34's were always showing up. Roadster pickups/trucks were more prevelant than roadsters in many areas because they were cheap commercial vehicles, even in the big (AA) trucks. Cold, wet climates didn't have many roadster buyers, but they still had lots of cheap trucking outfits. Build whatever pickup you want-they've all been hot rods before.