Just wanted to bump this thread.

A question above asked about the 21j (v1-2-3) carb bodies being all the same... do all the carburators that have a j on them only say 21j!? Or do the 21j2 j3 say 21j2 21j3 on the body? Because I have a lot of os carbs and even some from newer engines that should have the j2 or j3 set up, but the body on say 21j. How are we to know if it's the v1-2-or 3 if All the carbs only have the 21j only. I surely have a couple 21j version carbs of each j1-2-3 but I can't tell a difference between them when they all say 21j and that's it. Also I do have a few 22 carbs, can these internals be changed out with the better needles from the more consistent needle set ups from my other 21j carbs?