I have a Rail King 4-6-4 Hudson Steam Eng. ...
the main purpose of the pilot truck on steam locomotives is to steer (nudge) the front end when entering a curve when running at mainline speeds. at higher (passenger consist) speeds, 4 wheel pilot trucks are more effective in this role, so generally speaking, 2 wheel pilot trucks were more often found on smaller driver, slower speed freight locomotives, while 4 wheel pilot trucks were mostly found on larger driver, higher speed passenger and dual service locomotives.
with the 4 wheel pilot truck and 79" drivers, as GRJohn already mentioned, NYC Hudsons were primarily used in passenger service. if you want a freight locomotive from the same era, look at wheel arrangements such as a Mikado (2-8-2) or Berkshire (2-8-4).
cheers...gary