Wheels sizes and brake rotors - whats compatible?

I have a GPZ750A1 83 model and want to get new rotors and calipers for the front as mine are in really poor condition.
There are 7 allen bolts on the rotors.

I might be able to get to a 85 Gpz900, which only has 6 bolts on the rotors, so these will not fit on the 750's wheel, unless I get the 900's front wheel as well.

Does anyone know if the wheel and tyre sizes are the same on these two different bikes?

Many thanks

83-85 GPz750 has a 18" front wheel, 85 GPz900 has a 16" front wheel.

If you want to swap parts around, then I suggest becoming intimately familiar with the parts diagrams at kawasaki.com.

You're in a minefield but there's a way out.
I bought some sr650 discs for my 500 'cos they only had a few hundred miles on 'em.
When I went to fit them, the bloody hole in the middle was too small to fit on my front wheel.
Sooooooo....grind off all the [non magnetic rivits] on the FRONT of the old discs and the BACK of the new discs.
Swap the middle bit, use A4 ss [8*2] 6mm bolts.
As long as the "rotor"? [disc] is the same size or bigger, no problem.:woohoo: :woohoo: