Welcome Brian -- as you can tell, only the coolest of Stovebolters are allowed to own AD 1-tons

So welcome to the elite!
The guys are correct about the engine -- the tell-tale signs of the later (post-1954) 235 are how the valve cover attaches -- four screws on the flange versus two acorn nuts on the top of the valve cover, along with the pushrod cover that go all the way up around the spark plugs. Prior to 1954, the earlier model 235 (the splasher 235 developed for the war trucks) was optional for the 1-tons and bigger trucks -- my '49 3800 still has it's original splasher 235 that the original owner special ordered with the truck.
Anyway, you got a great deal on that truck! And welcome to the Stovebolt Community! You're family now so don't be a stranger! And be sure to check out all of the web site, not just the forums.
Regards,
John