um, i think your getting confussed, and you need to replace that currently in your xbox 40pin 40wire, with a 40pin 80 wire one, as far as i no there are no 80 pin ones, you want a 80 wire on though.
40-pin IDE cable is standard in every Xbox......the reason Microsoft did this was to save money.....10 cents per xbox saved by not upgrading to the 80-pin cable x 1 million+ units = over 10 million dollars + saved