Here's a little story I like to tell regarding pod filters v OEM airboxes :
A few years ago I was taking care of work friends' 93 Ducati 900 Supersport - a beautiful bike. He had bought it just before leaving for Asia on a multiyear expat assignment. I got her running and took her out for a ride where I discovered a giant flat spot in performance at full throttle. I wasn't comfortable messing around with a Ducati or carbs at the time and with no Ducati dealers nearby, I went to the the local powersports dealer for help. The girl behind the counter told me they don't work on Ducatis, but added "My dad works on old motorcycles, but I'm not sure that yours is old enough". She gave me his name and number, I called him up and told him about the bike, he agreed to take a look.
I rode the bike over to Joel's house and waited for him to arrive, which he soon did riding an old Vespa. We chated for a bit outside, he agreed to work on the bike, then he opened his garage door, revealing the largest collection I have ever seen of vintage motorcycles: all makes, models and sizes. It turns out that Joel is the retired founder and owner of the powersports dealer I had visted, which happens to be the largest in Delaware, and Joel is an avid collector or motorcycles. He has a side business (
http://www.retrotours.com) in which he organizes tours which you ride on his vintage bikes.
Anyway, Joel keeps the bike for a week or so and when I get back in touch with him, he explains that a previous owner had removed the stock airbox, replacing it with K&N pods. The PO had not rejetted the carbs afterwards, as a result the bike ran lean at full throttle, which explained the lack of power I had felt.
Joel said that he certainly could rejet the carbs to restore the power at full throttle, but he suggested another course of action. Pods are great if you are expert rider racing on a track and you need the last bit of horsepower at high rpms. But if you want a bike that runs well throughout the rpm range, find and reinstall an OEM airbox, which on the Ducati 900 SS, in addition to being expertly designed to maximize overall performance, is a work of art.
I was able to find a used airbox from a guy who specializes in building high performance Ducatis for racing. Joel installed it, after which the bike was an absolute dream to ride! I wish she was still in my garage but my buddy's brother came up from Atlanta a few months later and rode her away.....
Long story short, while the OEM airbox/filter assembly on the CB550 is perhaps not as aesthetically pleasing as you might want, you will lose something in terms of rideabily and performance throughout the rpm range of the bike if you decide to go with pods.
Good luck with the rebuild! I'm in the midst of my own CB550 rebuild.