Between my bike Honda - Yamaha... I've never really seen a 'full engine' rebuild kit.
There are a few 'kits' out there for different parts of the bike.
As for the Engine, I'm rebuilding an XS650 motor right now,
this is what I'm doing for it and this is what i did for the 360.
- Factory manual AND Clymer (You're lucky... they can be found digital for the CB360.. Gotta buy em for the Yamaha)
- Complete Gasket kit w/ Valve Seals.
- Oil Seal kit (ex: For the XS650 that 7 - 10 Seals total, Case seal for each spindle, ie crank/ drive srocket etc..).
- Cam Chain and Possibly; Guides.
- New set of Rings and a (Flexhone) - 67mm Carbon Oxide I'd say one from anywhere from 180 - 400 Grit. (This is assuming your jugs are use-able and to spec.)
- Valve Lapping Cream and a Lapping Stick - (This will help 're-seat' your valves. Cutting them is a bit more Thorough, but, this alone will to the job.)
- Valve Compressor - (Can rent from CheckerAuto or buy one off Amazon for cheap. Has to be the large 'C-Style)
- Refer to your manual though, check all your tolerances and spec. and replace as needed.
- If you're trying to get real down and dirty, get yourself a pressurized blaster tank from HF and drop some Soda Media in there and blast away your parts.
Flip the head over and blast all the carbon and grim off. As well as everything else.
That's your Rebuild Kit.