Anything bigger than a 28mm on a trail bike is gonna hurt you. Even with a stroker. The bigger carb bores you throw at it, the less bottom end it will make, and the more top end it will make. A lot of people work on the mis-conception that if you increase cc, or port duration, or stroke, or compression, that you have to have all these honking big parts. The fact of the matter is, you make a bike go fast by matching up the parts, making the motor work efficiently, and tuning it properly.
Doug Eichner, raced mickey Thompson indoor series back in the mid 90's. Saw him at the sand dunes in Oregeon in the summer of 1994. Raced some heavily built banshees, and other 250r hondas up boxcar. Crushed them, absolutely blew them away. Why??????????????? Well built factory race team motor, still under 260cc, still stock stroke, tuned well, right part combinations, and great suspension.
We need to get of this, I like em big, now I think its fast, lets go pee on stuff kick that everyone is on.