Once you modify the mufflers, the back pressure is reduced and the engine will be a bit sluggish on the bottom end besides not sounding that great.
You can squeak a little more out by opening up the right baffle only at the rear of the muffler, but any more than just a small amount will sound crummy.
Many have done it and many have found out that it doesn't work. Add a tuner and get some slip ons is the best way.
Your bike being a 2000 would sound a bit better with a set of the stock 07 slipons on it. They can be had cheap in most cases $30-$50 and they flow more than the original 2000 mufflers do . They have a better sound to them also.
