If you get a new carby thats a few mm bigger wouldn't you have to get a new manifold? people are sayen "yeh get a 26mm" but they never say anything about a new manifold do you have to??
You ask to many questions lol, yes you either buy a matched manifold or hone it out. Man google is a wonderful thing and search on this website will answer alot of your questions, so maybe instead of asking so many q's do some research first and if this doesn't help then come and ask.