Kooks 09-13 1-7/8 x 3 Header & Catted Y-Pipe Chevrolet Silverado 1500 LTZ WT LS LT XFE

Kooks 1-7/8" x 3" Long Tube Headers & Catted Y-Pipe for 2009–2013 Chevrolet Silverado 1500 & GMC Sierra 1500 4.8L/5.3L/6.0L

The Kooks 2855H420 1-7/8-inch long tube headers and catted Y-pipe kit delivers the complete bolt-on exhaust upgrade for 2009–2013 Chevrolet Silverado 1500 and GMC Sierra 1500 trucks with the 4.8L, 5.3L, or 6.0L 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 a high-flow 3-inch to OEM outlet catted Y-pipe that connects directly to the stock mid-section for unrestricted exhaust flow from low-end torque to high-RPM pulls.

Handcrafted from T304 aircraft-quality stainless steel with 3/8-inch laser-cut flanges, full TIG welds, and 300-cell metallic substrate catalytic converters, this system supports up to 700 HP while maintaining 49-state emissions compliance and improving throttle response for quicker acceleration during towing up to 10,000 lbs or daily highway passing. The precision design preserves ground clearance and heat management for work-ready trucks without sacrificing the deep V8 rumble that enhances cabin experience.

For Silverado and Sierra owners with 4.8L, 5.3L, or 6.0L engines seeking immediate power and torque improvements with durable, emissions-legal construction, the 2855H420 kit unlocks the engine's full potential for job sites, trails, or performance driving.

Key Features

• 1-7/8-inch equal-length mandrel-bent primaries for optimal scavenging
• 3-inch catted Y-pipe with high-flow metallic substrate
• Full T304 stainless steel with TIG welds and 3/8-inch flanges
• Merged collectors for maximum exhaust velocity
• Direct bolt-on to OEM mid-pipe no cutting required
• Dyno gains of 45–60 RWHP and 40–55 RWTQ on stock engines

Product Notes

• 49-state EPA compliant not for sale or use in California or CARB states without exemption
• Fits all cab/bed configurations with 4.8L, 5.3L, or 6.0L V8
• Includes O2 sensor extensions and EGR provisions

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

Warranty: Limited lifetime on stainless construction to original purchaser.

Installation Notes

• Professional installation recommended lift required
• Remove factory manifolds and bolt headers to cylinder heads
• Connect Y-pipe to collectors and OEM mid-section with supplied hardware
• Torque flanges to 25-30 ft-lbs and run drive cycle for ECU adaptation

This Part Fits

Note: Fits all cab styles and drivetrains with 4.8L, 5.3L, or 6.0L V8. Excludes 6.2L.

What's Included in the Purchase

• (2) 1-7/8" x 3" Long-Tube T304 Stainless Headers with Merged Collectors
• (1) 3" x OEM Outlet Catted Stainless Y-Pipe
• Gaskets, Stage 8 Locking Header Bolts, and Hardware Kit
• O2 Sensor Extensions
• Detailed Installation Instructions
• Part Number: Kooks 2855H420

Why Choose Kooks?

• Over 60 years of exhaust engineering with NHRA, NASCAR, and SCCA championships
• Handcrafted in the USA from T304 aircraft-quality stainless steel
• Limited lifetime warranty and dyno-proven for reliable power

Frequently Asked Questions

• Q: Does this fit my 2010 Silverado LT 5.3L?
  A: Yes, direct bolt-on for all 2009–2013 Silverado/Sierra 1500 with 4.8L/5.3L/6.0L
• Q: Will it cause a check engine light?
  A: No, catted Y-pipe and extensions maintain proper O2 sensor function
• Q: What power gains can I expect?
  A: 45–60 RWHP and 40–55 RWTQ on stock tune, more with ECU optimization

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.