On 2000 12's the starter gear is internal and when you have the crank stroked and use aftermarket rods, the journal, Rods, and inparticular rod bolt head come a little too close to the starter gear. Therfore a small portion of the starter gear teeth must be machined down to give it the clearance for the big end of the rod. 2002-2005 ZX-12's have a little different set up and I think most people just run stock rods. I have seen
stock rods break clean under 250HP even though most people say they are good for 300-350HP, so I did not want chance it.