It depends. If the ball size is the same, your chances are fairly good. But the thickness of the crown race, length of the flange on the cup, and presence or absence of any seals can also affect things.

But there are still plenty of decent headsets from Tange, Hatta, etc. available with 27.0mm JIS crown races. Pick one with the stack height closest to your current headset. Use shorter rather than taller if no exact match is available, as you can always add spacers to take up any slack.