Unless you planning some pretty severe frame mods or a hardtail, the Cyclex carbs don't fit, and I have yet to hear an independant report of them actually performing better than the stockers. I don't think there are any later model factory cbr carbs that are a good fit/match for these motors either. That leaves you with a few choices, a set of Mikuni vm26, 28, 29's (29's are gonna cost ya). Old Suzuki's and Kawasaki's are gonna be the donors and you will have to find adapter intake boots to make them fit...or Keihin CR's (these are gonna really cost ya!) There are a few guys on here who have had good success with Mikuni RS34's, but it takes a pretty radical engine build to warrant their use. For your basic, 836cc, cam, and a little head work, the stockers hang in there surprisingly well with some tuning.