I am working on the same thing you are, I am currently switching from 13/38 to 14/38. I know Killer250R is running 14/38 now with his LRD 330 and has ran a higher ratio so hopefully he will chime in and give you some insight. I have messed with smaller bore carbs and all kinds of stuff trying to get the thing where I want it, the thing has super smooth power but gets me in trouble sometimes because it accelerates so hard I don't realize how hot I am coming into corners. Hopefully it will tame the thing down a touch, stretch the gears out some and give me a little better traction, it's awesome to ride when I'm fresh but when I get tired is when she starts getting me in trouble.