Well the engine casting number is 3837004, which I come up with as a '55-'57 235/261. All the clues are pointing to 235. The number behind the distributor appears to have 2 different numbers stamped one over the other, and the predominant one appears that it might match the title. I found a decoder for the VIN and it comes up as a '50 4100 series (1-1/2 ton) 137" wheel base built in Flint in the month of May.

Some of the wheels are looking a little spooky also. I know that Chevy used these same ones for a while, so I can probably dig up some better ones, but this might also be a good time to change out to a different kind of wheel. I am not real fond of the split rims, but as long as they are in decent shape they don't bother me too much. Are there other wheels available out there, used or new, that could be used?