I think I am, in fact, trying to make this the longest build thread.
The CB750 wheel as a whole will not work on a 550 without major modification that is frankly not worth it. I ended up starting from scratch on the wheels. Stock 550 hubs stripped and powder coated with new bearings and new spokes to new aluminum rims. Unfortunately my stock pipes are too beat up from years of use to use on the bike. I did come across a set of 77-78 pipes in perfect shape so I am stuck with those until I make my own 4 into 4 mufflers. External oil lines made, tank painted, oil cooler installed, bike wired, carbs and filters installed etc... Only a few things left before she is road worthy.
Also, something something about time flying...