Ok so I don't know the answer to your question so take this at face value, I had read somewhere that when Willys introduced the the CJ5, they had the CJ3B available at the same time, and the price was just a tad different, it was close enough that you would be silly to buy the 3B because of the extra size of the 5. I'm not sure on the roll out date there, I have a 52 M38A1, so the cj 5 had to in there somewhere. Is it possible that the CJ3B replaced the 3A in 52, and the 5 replaced the 3B in like 54? I'm guessing and Bill will know, but I think the 52 3A may have been close to the end of the road.?? Just guessing.