I agree with Polaris_Parts_MN, if you looking for more performance by doing a big bore then for maximum gains you will also need porting and head mods that go along with it, not to mention a set of pipes that will compliment all of the above mentioned work, dollars start flying out pretty fast when wanting to do all of this that is for sure.Polaris_Parts_MN said:yeah it's not going to be cheap. no point to bore out cylinders unless you have a cylinder that is scored bad. boring cylinders to gain performance (which is what I assume you are wanting to do...) gives you the least bang for your buck.