I have a TT350, wouldn't get rid of it for nothing. It's easy to make streetlegal. You would not gain enough by using the XT350 stator and flywheel. The stock stator is enough to power the stock 55W headlight and the tailight. The cheap way to do it would be to get a halogen headlight and run a 35W H4 in it. Get a rectifier put it in line and change the taillight to an LED, get LED blinkers and your home free, don't forget the horn. I used to run mine using the cheap way, but now I have a Universal Baja Designs system on it, Baja Designs also rewired my stator for higher output. Works great. I don't think Clarke has a bigger tank, I believe their's is stock size 2.6gallon. But the stock tank with a properly running bike should get you anywhere from 80 to 120 miles. I've gone 140 miles before on a tank (would not recommend it, it was scary out in the middle of nowhere and no gas station in site).
Do it in the Dirt!
1974 DT250, 1980 TT500, 1986 TT350, 1993 KLX650C, 03 KTM450EXC