Well, I've only worked on the CB550 clutch. A few years ago, at that. So, someone else may have a better answer. But, I know the clutch was a major design renovation between the CB500 and the CB550 as the 500 had parts from an older 350 twin design and was quite marginal for the 500's power. I really wouldn't expect any of the clutch parts to interchange between CB500 and CB550. I'd be rather fearful of bringing the 500s clutch foibles into the 550. But, I could be wrong... Doesn't the 550 have 8 friction plates? I think that's what I count in the Honda Manual.
Best of luck, though...