Did you have the carbs synced after the change?
that's interesting, as I have always had annoying vibe issues that I've mostly sorted. Might check my airbox isn't causing vibes by padding the filter out slightly where it rests on the bottom of the box or something.
I mean the filter inside the box, not the box itself, sorry. I wonder if the filter isn't a snug fit and is vibrating slightly. I remember tightening the airbox up when I bought the bike which helped the vibes a little.