88's in Oz had conventional forks, and the Oz 89's had the 43mm USD's (as mine has above).
Some Pro's reckon the 46mm conventionals (found on 1989 US models) are far superior. You can grab a set and legally fit them.
Ando has an import bike with them on.
I've ridden both and I havent really noticed - but I am just a hacker.
One other difference is the rear shock on the 89 has a fork lower end, whereas the 88's have an eye end bearing.
Oh and the tank is different on the 89's too... it sits lower.
There could be other changes - but I am not really sure. Actually I think the stator is different from memory.....
Other than that mate - just BNG ... lol