Rear tires for KZ1300 (1982)

Do all years fit the same tire size?

I have seen photos of KZ having all sorts of different rear tire sizes, including radials.
Are there radials fitting rear OEM wheels? There are for front for sure. What would involve converting to radials?

What tire sizes can be fitted on the OEM wheel?

I have a 150/90 - 15 tire in great shape from my other bike. The front tire fits KZ perfect - same size. Would be awesome to be able to use the other one as well.
What has to be done to fit it?

Are there ane interchangeable straight bolt on wheels from other bikes?

Stan

Would not suggest you go smaller in rims, keeping in mind the Ground Clearance ! I've always run the recommended size for the 18" front but for many years now have been putting a 150-70 on the 17" rear - no issues, ever. Should be no concerns about radials as the rims are for tubeless.

Thanks! One the time comes I will go for one in this size as well. It is too bad I can't fit the one I have... Vmax has 15 inch wheels so it's too small...