Originally Posted by
ak08820
I don't have the means to measure the dimension 'L'. Even if I take it out, the difference betwen 26.4mm and 27 is very small. I wonder if a Fuji expert can tell me whether I need 26.4 or 27 size. I may not replace the crown race, if I get a new headset, if I can get away with it. Though, I have done it once and it is not that difficult.
If you can find an identical headset to replace the worn parts on your current one, you will not need to change the crown race (assuming it is in decent condition). Otherwise, there is no substitute for measurement. Japanese headsets of that era were available in both JIS and ISO dimensions.