Originally posted by thbirks
Good point, The crown race went on just as it should. So I quess i have the right headset. The frame is a Miyata 110, probably from the late '70s, if anyone's wondering.
I'm thinkin a Myita of that vintage would have had the JIS with 30.0 cups and 27.0 crownrace. On stuff ot that vintage and origin,it pays to measure.