" . . . ‘55 and newer would have to have them relocated to use in the ‘47—‘54 trucks, correct. . . "

I think that the 1955 First Series 3100 trucks had the water pump in the "correct" (earlier position).

Hopefully, someone will correct/confirm this?

Tim
1954Advance-Design.com
1954 3106 Carryall Suburban
1954 3104 5-window pickup w/Hydra-Matic
The 216 and early 235 engines are not "splash oilers" -- this is a splash oiler.