All wheels (chrome rim wire, aluminum rim wire, seven-spoke cast aluminum) swap on all years.
Drum fronts on early models are on their own.
Pre '77 & post '77 fronts have different (offset) brake discs, the wheels swap but not the discs.
Drum rear wheel into rear disc frame needs the rear drum frame swingarm too.
Disk rear wheel into rear drum frame needs the rear disc frame swingarm and also needs brake master-cylinder lugs welded to the frame.
Handling differences on swapping rear wheels:-
Standard rear tire is 110/90-18. Special rear tire is 130/90-16. Because the Standard tire is narrower it corners quicker. Because the Special tire is wider it's steadier in a straight line. Overall gearing will not change as the two tires are essentially the same outside diameter.
Left-side front disc brake (omitted on North American models only) can be added by bolting another disc to the left side of the wheel (the bolt holes are there) and the left-side caliper from an SR500, XS750, XS850 or XS11 (the fork lugs are there) and adding the other brake line & a double-length banjo bolt. XS650 stock master cylinder still works. The system needs very careful bleeding, stainless steel wire braid hoses improve the feel.