2) Drive it around or show it to people. If they oooh and aaaah at it, it's a CJ-3A. If they ask what that hideous thing is, it's a CJ-3B.
3) Look at the hood and front grill. If it's tall, and I mean abnormally tall, it's a CJ-3B, if it's short, it's a CJ-3A.
4) Look under the hood. If it has a flat head on the engine, looks like you could line up beer cans and not have them fall off, it's the L head 134 that came stock in the CJ-3A. If the beer cans will fall off the engine, it's an F head 134 found in the CJ-3B. (This excludes swaps where people put the F head in the CJ-3A's, but you can tell them by the cutout to put the air cleaner on top of the hood.
The grill does'nt look really tall. But what would I know. The 85 CJ 7 parked in front of the 53, has almost the exact dimensions. The beer cans wouldn't stay any better on a bar! Maybe this might help? Thank you