Tom,
Nice find.
Can you post a photo of the front of the engine, or from the side of the front of the engine (to show the orientation of the water pump relative to the head?
The cooling systems in 1947-55 trucks benefit from relocating and replacing the water pump on 1955 and later 235/261 engines (I assume this is also the case for use in a 1942 truck). This conversion might have been done already. If not, Pre '68 Dave (on this site) makes/sells a water-pump adapter-plate (with instructions).
