Ford was contracted to produce "jeeps" during WW2 because the military demand was so high. (souce Fifth Gear ep:14x6)
The wiki does state anything about which engine they use and when the engine was produced. I'm going to take a wild guess here, and think they had L4 in there, thats why they could meet the torque requirements, that and the demand for steel was so high back then.
Trying to steer this thread back to the original topic/question. All I've read on here so far is that everyone is talking about the "car" not the engine.
http://www.allpar.com/mopar/40.html