Far as I remember reading the cylinders should work however the cylinder sleeves may need to be clearanced for the crank. The pistons will need the skirts cut to clear the crank. You will have to make sure you have correct clearance at TDC. There are aftermarket pistons available that should work although they are a bit costly.
450 pistons sit 2mm lower in the bore, ie low compression, less than ideal combustion, no squish/quench, but you can run it without issue provided the pistons are wisecos etc, as they need to have slightly narrower skirts compared to OEM 450 pistons which would contact the crank. The cylinders and sleeves themselves are completely interchangeable, pistons must be aftermarket with clearance between piston skirt and crank. The issue of sitting 2mm lower in the bore can only be resolved with custom 2mm longer rods or by decking the cylinders 2mm which throws the cam timing out and requires machining cams for adjustable cam gears to correct the timing and then you have issues with cam chain tension etc, whole can of worms that is best avoided. If you're in a bind and just need to get it running, as set of CB450 wiseco pistons will do that for you and will work relatively well, a set of OEM 450 pistons can be made to work by grinding away the correct amount of piston skirt, have to try to get the piston weights the same if you go this option. There are a few other options from some Kawasaki KZ bikes (I think KZ 900/1000) which can be made to work, usually for big bore applications though.
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