The crank pulley bolt is what holds the pulley on with a woodruff key or keystock keeping it from rotating. You should first see if you can get the crank pulley bolt loose. There is a plastic cover in your drivers side fender well that you remove to access it. It may be a real pain to get it off, you may have to take it to a shop so they can use a real high foot pound impact gun to break it loose.
A lightened pulley is nice, it doesn't necessarilly have to have holes in it to be lightened, sometimes they are just shaved down or other accessories shaved off of the pulley. An underdrive pulley is a bit more of an expense and I don't really think that they are necessary or needed. With people debating on whether or not their main bearings get damaged due to them not having any dampening ability to them it's not really worth having that question in your head for a couple of horsepower. Not to mention that your voltage will be lower at idle. Just my thoughts on it since I own an unorthodox underdrive pulley and my zc has a shimmy when it starts which was not there when I bought it.
A lightened pulley is nice, it doesn't necessarilly have to have holes in it to be lightened, sometimes they are just shaved down or other accessories shaved off of the pulley. An underdrive pulley is a bit more of an expense and I don't really think that they are necessary or needed. With people debating on whether or not their main bearings get damaged due to them not having any dampening ability to them it's not really worth having that question in your head for a couple of horsepower. Not to mention that your voltage will be lower at idle. Just my thoughts on it since I own an unorthodox underdrive pulley and my zc has a shimmy when it starts which was not there when I bought it.
