-10%
Kooks 11304300 1-3/4 inch long-tube headers for 2005-2009 Mustang GT GT500 full set
3 inch x 3 inch x 2-1/2 inch OEM green catted X-pipe from Kooks 11304300 kit
Click to zoom in

Kooks 05-09 Ford Mustang GT 4.6L 3V 07-09 Shelby GT-500 Full 3in Cat-back Exhaust

Kooks Headers
KSH11304300
842422124755
Catback
2 Units In Stock - Ships Next Business Day
$ 1,664.46 $ 1,498.01
$ 1,498.01

Kooks 1-3/4" x 3" Long Tube Headers & GREEN Catted X-Pipe for 2005 and 2009 Ford Mustang GT 4.6L 3V & Shelby GT500 5.4L Supercharged

The Kooks 11304300 1-3/4-inch long tube headers and GREEN catted X-pipe kit delivers the complete bolt-on exhaust upgrade for 2005 and 2009 Ford Mustang GT with the 4.6L 3V V8 and Shelby GT500 with the 5.4L supercharged V8, replacing factory manifolds to unlock dyno-proven gains of 45 and 60 rear-wheel horsepower and 40 and 55 lb-ft of torque through equal-length primaries, merged collectors, and a high-flow 3-inch x 3-inch x 2-1/2-inch OEM GREEN catted X-pipe that connects directly to the factory exhaust for seamless integration and unrestricted flow from idle to redline.

Handcrafted from T304 aircraft-quality stainless steel with 3/8-inch laser-cut flanges, full TIG welds, and 400-cell metallic substrate GREEN catalytic converters, this system supports over 800 HP while remaining 49-state emissions compliant and preserving the Mustang's aggressive V8 soundtrack without drone. The precision design maintains factory ground clearance and heat shielding for daily-driven performance cars.

For S197 Mustang GT and GT500 owners who demand championship-level performance with street-legal reliability, the 11304300 kit is the race-winning, complete bolt-on solution trusted by Coyote and Shelby enthusiasts worldwide.

Key Features

  • 1-3/4-inch equal-length mandrel-bent primaries for maximum scavenging
  • 3-inch x 3-inch x 2-1/2-inch OEM GREEN high-flow metallic catalytic converters
  • Full T304 stainless steel with TIG welds and 3/8-inch flanges
  • Merged collectors for optimal exhaust velocity
  • Direct bolt-on to OEM exhaust no cutting required
  • Dyno gains of 45 and 60 RWHP and 40 and 55 RWTQ

Product Notes

  • 49-state EPA compliant not for sale or use in California or CARB states without exemption
  • Fits 2005 and 2009 Mustang GT 4.6L 3V and 2007 and 2009 Shelby GT500 5.4L supercharged
  • Includes O2 extensions and all necessary hardware

California Proposition 65: Contains chemicals known to the State of California to cause cancer or reproductive harm.

Warranty: Limited lifetime on stainless construction and 25,000 miles on catalytic converters to original purchaser.

Installation Notes

  • Professional installation required lift and exhaust experience needed
  • Remove factory manifolds and bolt headers to cylinder heads
  • Connect catted X-pipe to collectors and OEM mid-pipe
  • Torque flanges to 25-30 ft-lbs and run drive cycle for ECU adaptation

This Part Fits

Year Make Model Submodel/Engine
2005 and 2009 Ford Mustang GT 4.6L 3V V8
2007 and 2009 Ford Mustang Shelby GT500 5.4L Supercharged V8

Note: Fits all 2005 and 2009 Mustang GT and 2007 and 2009 Shelby GT500 coupe and convertible with factory exhaust. Manual or automatic.

What's Included in the Purchase

  • (2) 1-3/4" x 3" Long-Tube T304 Stainless Headers with Merged Collectors
  • (1) 3" x 3" x 2-1/2" OEM GREEN Catted Stainless X-Pipe
  • Gaskets, Stage 8 Locking Bolts, Clamps and Hardware
  • O2 Sensor Extensions
  • Detailed Installation Instructions
  • Part Number: Kooks 11304300

Why Choose Kooks?

  • Over 60 years of championship-winning exhaust engineering
  • Handcrafted in the USA from T304 aircraft-quality stainless steel
  • Limited lifetime warranty and dyno-proven performance

Frequently Asked Questions

  • Q: Does this fit my 2007 Shelby GT500?
    A: Yes, direct bolt-on for all 2007 and 2009 GT500
  • Q: Will it cause a check engine light?
    A: No, GREEN cats and extensions maintain proper O2 function
  • Q: How loud is it?
    A: Aggressive V8 roar at WOT, refined and drone-free at cruise
  • Do Kooks headers require a tune after installation?
    Yes. A professional tune is strongly recommended after installing long tube headers. The significant improvement in exhaust flow changes air fuel ratios and requires ECM recalibration to achieve optimal power output and safe operation.
  • Will these headers void my factory powertrain warranty?
    Under the Magnuson-Moss Warranty Act, a manufacturer cannot void your vehicle warranty simply because you installed an aftermarket part unless they prove the component directly caused the failure. Consult your dealer for specifics on your situation.
  • Q: Do these Kooks headers require a tune after installation?
    A: Yes. A professional tune is strongly recommended after installing long tube headers. The significant improvement in exhaust flow changes air fuel ratios and requires ECM recalibration to achieve optimal power output and safe operation.
  • Q: Will Kooks headers void my factory powertrain warranty?
    A: Under the Magnuson-Moss Warranty Act, a manufacturer cannot void your vehicle warranty simply because you installed an aftermarket part unless they prove the component directly caused the failure in question. Consult your dealer for specifics.
  • Q: What warranty does Kooks provide?
    A: Kooks products are backed by a limited lifetime warranty to the original purchaser against defects in materials and workmanship. Racing and competition use applications may have specific warranty exclusions. Contact Kooks Performance directly for warranty details.

Shipping & Handling

  • Method: UPS or Fed Ex Ground.
  • Availability: Typically ships same day or next if in stock.
  • Packaging: Heavy-duty box with foam protection.

Request For Information

Have questions about Kooks 05-09 Ford Mustang GT 4.6L 3V 07-09 Shelby GT-500 Full 3in Cat-back Exhaust? Fill out the form below and we'll get back to you by the next business day.
Catback

Catback

A catback exhaust system replaces everything from the catalytic converter back, covering the mid pipe, muffler, and tailpipe section in one bolt on upgrade. This collection covers catback systems for trucks, Jeeps, muscle cars, imports, and performance SUVs, giving you a straightforward way to improve sound, exhaust flow, and rear end styling without touching the factory catalytic converters or front pipe. Catback systems are available in stainless steel and titanium construction, with dual rear exit, single exit, and quad tip configurations, and a range of sound levels from mild touring tone to aggressive track character. Whether you want a deeper daily driver sound or a full track ready exhaust note, you will find a matched system for your platform here. What This Category Covers This collection includes complete catback exhaust systems, cat-back kits, dual rear exit systems, axle back adjacent catback upgrades, stainless steel and titanium exhaust systems, and street, tourin...

View Catback Products
Exhaust Systems

Exhaust Systems

Performance exhaust systems for cars, trucks, SUVs, and Jeeps are stocked at Black Ops Auto Works. Shop cat-back systems, axle-back systems, turbo-back systems, headers, downpipes, mid-pipes, mufflers, resonators, catalytic converters, exhaust tips, exhaust valve controllers, oxygen sensors, exhaust brakes, and motorcycle and powersports exhausts for Mustang, Camaro, Challenger, Corvette, Silverado, and Super Duty platforms. Every product is filterable by exhaust position, material, pipe diameter, and vehicle year, make, model, and trim so the correct fitment ships the first time. Black Ops Auto Works carries 7,441 exhaust SKUs across every position of the exhaust system. What This Category Covers Exhaust upgrades change sound, appearance, and in some cases power. Exhaust fitment depends on engine, drivetrain, and factory exit position, so confirm the exact platform before ordering any exhaust component. Exhaust Position Cat-back, axle-back, turbo-back, and header-back systems e...

View Exhaust Systems Products
Ford Mustang Parts & Accessories

Ford Mustang Parts & Accessories

Ford Mustang parts and accessories for every generation are stocked at Black Ops Auto Works. Shop cold air intakes, cat-back and axle-back exhaust systems, headers, coilovers, lowering springs, sway bars, brake pads, brake rotors, big brake kits, carbon fiber body parts, wheel spacers, fuel system components, and lighting upgrades for the Fox Body, SN95, New Edge, S197, and S550/S650 platforms, including EcoBoost, GT, Mach 1, Shelby GT350, Shelby GT500, and Dark Horse. Every product is filterable by year, make, model, trim, engine, and drivetrain so the correct part ships the first time. Black Ops Auto Works carries 2,101 Ford Mustang SKUs across suspension, brakes, exhaust, intake, exterior, and drivetrain categories. What This Collection Covers The Ford Mustang has run through six generations since 1964, and each one uses different suspension geometry, brake hardware, exhaust routing, and body dimensions. This collection groups parts confirmed to fit specific Mustang generatio...

View Ford Mustang Parts & Accessories Products
Kooks Exhaust

Kooks Exhaust

Kooks Exhaust parts and accessories for American muscle cars and performance trucks are stocked at Black Ops Auto Works. Shop stainless steel long tube headers, shorty headers, catted connection pipes, mid pipes, X-pipes, H-pipes, cat-back systems, axle-back systems, resonator deletes, GREEN catalytic converters, O2 extensions, clamps and header hardware for Mustang, Camaro, Corvette, Challenger, Charger, Silverado, F-150 and Ram HEMI builds. Every product is filterable by year, make, model, trim, engine and drivetrain so the correct part ships the first time. Black Ops Auto Works carries 174 Kooks exhaust SKUs across vehicle-specific fitment, performance upgrades, replacement parts, installation hardware and custom build needs. What This Collection Covers Kooks builds vehicle-specific stainless steel exhaust components for naturally aspirated, supercharged and turbocharged V8 street cars, track cars and HD truck builds. The range includes complete header-to-tailpipe paths as we...

View Kooks Exhaust Products
Military & First Responder Discounts

Military & First Responder Discount Program

Black Ops Auto Works proudly honors active duty military, veterans, National Guard, reserves, police officers, firefighters, and EMTs with an exclusive 5% discount on all performance parts and carbon fiber upgrades. Verify instantly and start saving today.

Learn More & Apply

Your cart

×