If you are saying A4 then Partzilla shows only one and doesn't show any compatibility with other models. The part number is 21007 - 1048.
It is a shame Partzilla doesn't show compatibility for European models, like ZG or Z. It's an American company, maybe that's why.
I am putting an engine together from whatever available parts, so nothing is set in stone. The case is 1980, and comes with those small ignition pick up coils mounted to the upper case. A4, like your bike, has them on the right side of the crankshaft. So, I can make this engine to whatever I want, depending on availability. I am considering adding a second charger on the left, and pick up coils on the right like in the A4 model (if I find pick up coils and CDI, regulator would also need to be changed). I will be posting about it in the future to report and ask for advise. If I discover something regarding your needed rotor I will let you know.
1982 Kawasaki KZ1300 A4
1981 Kawasaki KZ1300 A3
assembling engine, chassis & electrical from 79 - 89 parts