All I know for sure is the 900-1000 have the same pipe spacing so they could interchange enough to at least mount to the engine. KZ650-750 have a narrower space between the cylinders, so pipes between those would line up to the engine. KZ550 has a narrower spacing yet, so nothing else will mount to it. This is just what pipes could be bolted to the engine. From there, no telling how they would work with the rest of the chassis.
321,000 miles on KZ's that I can remember. Not going to see any more.
