I just raced a 400ex bored to a 440 with cams, carb, exhaust, intake, everything. Also his friend had a yfz450 with cams, exhaust, intake, etc. They both whooped my ass! Not by very much that is. The 450 beat me by about 2-3 bike lengths, and the 440ex beat me by about 1-2 bike lengths. We were racing up sand mountain here in utah. All I have done to my bansh is K&n and re-jetted. It still pissed my off though! I am ordering my Trinity Exhaust in the next day or two. Then we will see.........