Get rid of the pod filters, install an OEM air box, and THEN tune your carbs. The carbs on these bikes, at least the 79's and later, depend upon the vacuum setup created by the OEM air box -- pods will never create the correct, functional, air-flow necessary to make the carbs run properly. Pods look neat, but they just don't work (see caveat, above, on years).
You can, however, use a K&N air filter (approx. $60?), if you want to increase the air flow. I have one in mine, but I would probably go with an oiled, UNI foam filter, instead, if I could do it over again -- less money? Cheers!
1979 CB750K (sold, 2012, but not forgotten)
1983 Kawasaki 440 LTD Belt Drive (sold, 2011)
1993 Kawasaki Voyager XII