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Kooks 1-5/8 in. Header and Off-Road X-Pipe Combo (99-04 GT)

Market Price $1,675.08 You Save 10% ($167.50)
Our Price

$1,507.58 (kit)

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  • Item 65529
  • MPN#11212000

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Features & Details

  • Increase Rear Wheel Horsepower and Torque
  • Includes Long Tube Headers w/ Matching Off-Road X-Pipe
  • 304 Stainless Steel Construction
  • For Off-Road, Track Use
  • Free Flowing Mandrel-Bent Tubing
  • Fits 1999-2004 GT and Bullitt Mustangs
Improve Horsepower And Torque. The Kooks Long Tube Header and Off-road Shorty X-pipe combo kit for the GT and Bullitt Mustang will balance out the exhaust pressure to increase flow over the restrictive factory exhaust system resulting in more horsepower, torque, and better throttle response.

Quality Construction. Manufactured from 1-5/8" mandrel bent 304 stainless steel tubing Kooks Long Tube Headers are TIG welded for strength, and feature a leak-free ball flange design to fit perfectly into the included 2.5" diameter 304 stainless steel Shorty X-pipe for excellent exhaust flow and performance.

Natural Finish. These Kooks Headers feature a natural stainless steel finish, which provides an aggressive appearance to your engine bay. This is not a heat-resistant coating, AmericanMuscle recommends the use of Exhaust Heat Wrap for high performance applications.

Recommended Upgrade. To realize the full power potential that this Kooks Long Tube Header and X-pipe Kit has to offer, AmericanMuscle recommends a custom tune with a Mustang Handheld Tuner to reprogram the vehicles computer (ECU) for proper operation.

Application. This Kooks Long Tube Header and matching off-road shorty X-pipe combo kit is designed specifically for the 1999-2004 4.6L GT and Bullitt Mustangs.

Technical Note: This Kooks product is intended for off road use, and is not legal for use in emission restrictive states.

Fitment: 1999 2000 2001 2002 2003 2004 Details

What's in the Box
  • Kooks Long Tube Headers
  • Kooks off-road shorty X-Pipe
  • Necessary Gaskets
  • O2 Extensions
Installation Info
Tech Specs
Will it fit my Mustang?
  • Bullitt - 01
  • GT - 99, 00, 01, 02, 03, 04

Most Helpful Reviews

5/5
Great sound and horsepower gain.

Installed on a 2003 Saleen S/C Car. Installation was crazy and almost impossible because of absolutely no clearance but after a whole lot of persistence they are finally installed. Without having it tuned ...

Read More
Helpful (3)

5/5
Sounds Amazing!!!

I have the Borla Stinger S Catback. These Headers made my exhaust sound amazing. Great Muscle car growl. I would recommend them for anybody.

Helpful (1)

Overall Rating 4.8 out of 5 stars
Read All 5 Reviews

Customer Photos (1) Submit Your Photo

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3 Questions / 3 Answers

Ask a Question

Will this setup work with slp loudmouth exhaust? And does it come with gaskets and hardware?

Chris

  • So because this system is designed to fit with the stock catback and the SLP catback is designed to fit with the stock midpipe, it would be safe to assume they are indeed compatible with each other! I will post the link to the SLP catback below: https://www.americanmuscle.com/slpexhaust.html

    JeffAM

Helpful (0)

Will the shorty x-pipe fit with my borla stingers?

Theresnowaybro

  • The shorty X-pipe in the Kooks header and Off-Road X-pipe combo will work with the Borla Stinger exhaust.

    KevinD92

Helpful (0)

Will this fit the Manual coupe?

CJNOVA

  • This system fits a manual or automatic car

    Kooks Headers

Helpful (0)

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Customer Reviews (5) Write a Review

Overall Rating 4.8

out of 5 stars

Installation Time:Weekend

Installation Cost:$500-$1000

  • Performance Gain 4.8 4.8
  • Fit 4.6 4.6



  • 5/5

    Installation Time: Weekend

    May 14, 2013

    Great sound and horsepower gain.

    Installed on a 2003 Saleen S/C Car. Installation was crazy and almost impossible because of absolutely no clearance but after a whole lot of persistence they are finally installed. Without having it tuned yet I could feel the Horsepower gain and the sound is awesome. Would definitely recommend these headers and x-pipe but plan a weekend or longer for install.

    saleen276

    Year: 2003 Submodel: Other Chicago, IL, USA

    Helpful (3)

  • 5/5

    Installation Time: Weekend

    July 10, 2017

    Sounds Amazing!!!

    I have the Borla Stinger S Catback. These Headers made my exhaust sound amazing. Great Muscle car growl. I would recommend them for anybody.

    NathanB

    Year: 2004 Submodel: GT

    Helpful (1)

  • 5/5

    Installation Time: Shop Install

    Installation Cost: $500-$1000

    July 29, 2017

    Sounds awesome!

    Would recommend this to anyone sounds really loud especially since I have it with the borla attack exhaust and you can feel the power when you get on it. My mechanic charged me $500 I know most shops charge around $800

    FranciscoJ

    Year: 2004 Submodel: GT

    Helpful (0)

  • 4/5

    Installation Time: Weekend

    June 22, 2017

    Looks headers

    Best sounding exhaust I've ever heard. worth the head ache was about a 10 hour install had the motor out doing other work though made it easier was a little disappointed that the o2 sensors didn't fit between header and auto trans had to relocate them and was told from the manufacturer that they wouldn't got because the headers were designed stupid a powerglide which was stupid because those were never put in a mustang but over all very glad a did it

    DanS

    Year: 2001 Submodel: GT

    Helpful (0)

  • 5/5

    Installation Time: Weekend

    June 20, 2017

    Long tube Kooks

    Kooks makes a first class header very difficult installation

    PatC

    Year: 2004 Submodel: GT

    Helpful (0)

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