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SKU: 2411H420 | UPC: 842422178789
Kooks 1-7/8" x 3" Long Tube Headers & GREEN Catted Connection Kit for 2004 Pontiac GTO 5.7L LS1
The Kooks 2411H420 1-7/8-inch long tube headers and GREEN catted connection kit delivers the complete bolt-on exhaust upgrade for the 2004 Pontiac GTO with the 5.7L LS1 V8, replacing factory manifolds to unlock dyno-proven gains of 45–60 rear-wheel horsepower and 40–55 lb-ft of torque through equal-length primaries, merged collectors, and high-flow 3-inch GREEN catted pipes that bolt directly to the OEM mid-pipe 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 700 HP while remaining 49-state emissions compliant and preserving the GTO’s aggressive V8 soundtrack without drone. The precision design maintains factory ground clearance and heat shielding for daily-driven muscle cars.
For 2004 GTO owners who demand championship-level performance with street-legal reliability, the 2411H420 kit is the race-winning, complete bolt-on solution trusted by LS enthusiasts worldwide.
Key Features
- 1-7/8-inch equal-length mandrel-bent primaries for maximum scavenging
- 3-inch 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 mid-pipe no cutting required
- Dyno gains of 45–60 RWHP and 40–55 RWTQ on stock LS1
Product Notes
- 49-state EPA compliant not for sale or use in California or CARB states without exemption
- Fits 2004 Pontiac GTO with 5.7L LS1 V8
- 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 pipes 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 |
|---|---|---|---|
| 2004 | Pontiac | GTO | Base - 5.7L LS1 V8 |
Note: Fits all 2004 Pontiac GTO with factory exhaust. Manual or automatic.
What's Included in the Purchase
- (2) 1-7/8" x 3" Long-Tube T304 Stainless Headers with Merged Collectors
- (2) 3" GREEN Catted Connection Pipes
- Gaskets, Stage 8 Locking Bolts, Clamps and Hardware
- O2 Sensor Extensions
- Detailed Installation Instructions
- Part Number: Kooks 2411H420
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 the 2004 GTO automatic?
A: Yes, direct bolt-on for all 2004 Pontiac GTO manual or auto -
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
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.
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