all light trucks had 6 bolt wheels, bigger had 8 bolt - 5 bolt is from a car, and the earlier car front hubs will fit the truck spindles, so some folks made that change 'back in the day', along w/ a car rear axle - V8's were an option starting in 55, but most common to find was the standard 6 - the fender mount spare was also a factory option - yes, that 58 could have been original w/ that option set
Bill