Pretty much any air cooled KZ or GPz four cylinder calipers will bolt on, all the way through the 84 GPz1100 and 85 GPz750 Turbo, after those years I don't have a clue.
I have 83 GPz750 calipers, 79 KZ1000 rotors, and a 96 GPz1100 master cylinder, on my 79 KZ750 twin, and it will out stop any stock Kawasaki up through 1985.
83 GPz750 had 10" rotors, 79 KZ1000 has 12" rotors, the 83 GPz750 calipers love that extra leverage
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