I want to see the bore and stroke measurements.  I am doubting the 330cc.  I'm going with what Quadster said. 

Trinity cylinder/head work with an .80 over 69mm piston?? Cause you know 250+80=330.

Piston is 73.95 mm bore is 74 mm not sure on stroke I was told it was a 330 if you call trinity they will tell you that they use to do a 330 for the lt250r. it may be only 295 cc i'll try to find out the stroke when I get time and put up some pictures.