The best carbs for the stock bike are the stock carbs intended for it. Of course a modified bike might benefit from alternative carbs, depending on its intended mission.
Honda designed and built an excellent all around street bike in the CB550F. It wasn’t the best race bike, or dirt bike, or tourer for coast to cost hauls (although it could be pressed to do the latter, if the rider could tolerate it).
The stock carbs are tuned and jetted to match flow characteristics of the stock exhaust and induction. Change way from stock exhaust and induction, and expect to also change the carb set up in some way, to return the engine to stock performance. If you intend to race a 40-50 year old bike with modern bikes in the same cc class well maybe mikunis will help with that, after experimenting with internal jet and fuel metering adjustments. Access to a dyno would speed that alteration considerably.
You didn’t say if your mikunis have a larger throat diameter. If not, I cannot see much help for a power improvement. Especially if there is no corresponding change to valve train and cam. If you are changing those, too, in order to win races, then adding 50 hp to the engine will stress it far more than original expectations and you will then want 2 or more back up engines as substitute for durability.
But, for a good fun street bike, the fastest and easiest way to achieve that goal is to restore to stock configuration.
If your goal is to impress passers by with your prowess to fit originally mismatched parts into an operating, if not well running, machine, then go ahead and adapt the mikunis, as you will learn quite a lot about your machine details and requirements along the way. But, know that it will only be “better”, if your mission goal is different from what Honda intended.
Cheers,
