In case you haven't done disassembly yet, the head set parts include a spacer between the two bearings as shown in the picture.
The bearings are identified as:
DKF DDR 90 62.05 A P66
Rough (Old caliper) measurements are:
O.D. 2.050
I.D. .985
Width .590
I agree that an upgrade to YZ "Style" bearings, whatever the flavor of the day, are wise.
Regards,
Robert