Ive just purchased my first New WR400 Y2K,first impressions GREAT! But it hes that big black ugly tail pipe! so this has to go for a ??????? what is recommended for the WR. I have also read you can fit a torqua valve in the header? Does anyone run one,and what will this give on performance? Its Enduro spec,would the bike be fitted with a restrictor pin?how can i tell. thx guys!