most intakes are the same...the AEM intake has a 3" diameter for the ITR - its the most popular. However, the Comptech Ice Box will yield only SLIGHTLY better gains.

headers...DC Sports, GReddy, etc they all use the same design. Now SMSP or Hytech build some incredible headers that would definitely give more power.

Exhausts...yet again, most of the mainstream companies have identical designs. Again, Hytech makes an exhaust for the ITR that is INCREDIBLE.