According to the boys on the CB750 Custom forum (
http://www.cb750c.com/), pods really won't work on the CV carbs, 1979+. Take a look over there, and you will see that they have grown tired of the topic, and they won't even discuss it anymore.
My advice would be to get an OEM air box, and use either a K&N Air Filter (around $60, still available), or a UNI foam filter which you would need to custom make to fit (much less expensive, same functionality, use the K&N oil kit on the UNI foam element). Cheers!
1979 CB750K (sold, 2012, but not forgotten)
1983 Kawasaki 440 LTD Belt Drive (sold, 2011)
1993 Kawasaki Voyager XII