The factory exhaust manifolds on your K2XX Silverado or Sierra are one of the first restrictions holding back your LS engine. This complete full kit pairs Speed Engineering's 1-7/8" longtube headers with a 3" off-road Y-pipe that connects directly to the existing cat-back location — replacing the restrictive factory exhaust manifolds and mid-pipes with a free-flowing stainless system designed for significant horsepower gains, improved throttle response, and a deeper, more aggressive exhaust tone. Dyno proven to deliver over 25 rear-wheel horsepower over stock.
Built from 304 natural stainless steel with mandrel-bent primary tubes, merge spikes, CNC-machined flanges, and full TIG-welded construction.
⚠️ Important Notes:
- Rear downstream O₂ sensors are not used — a check engine light for catalyst efficiency will appear and must be disabled via PCM tuning
- O₂ extensions: 2014–2015 trucks do NOT require O₂ extensions. 2016–2018 trucks DO require O₂ extensions. Select your model year at checkout
- Y-pipe is compatible with 6 speed and 8 speed automatic transmissions
- 2019 model year trucks: Classic body style only — NOT the new T1XX body style
- GM 2500/3500 6.0L applications: Use the 2007–2013 GMT900 exhaust products instead
Kit Includes:
- 1 Pair of 1-7/8" Stainless Longtube Headers
- 1 Three-inch Off-Road Y-Pipe / Connection Pipe
- 1 Set of Zinc-Coated Header Bolts (upgrade to stainless ARP bolts available at checkout)
- 2 MLS Exhaust Gaskets
- 2 O₂ Extension Harnesses (2016–2018 only — select your year at checkout)
Optional: Speed Engineering LS Spark Plug Wires and Plug Wire Fire Sleeves can be added at the time of purchase.
Features:
- Full 1-7/8" Primary Tubes with Merge Spikes — Full-diameter flow from cylinder head to collector for maximum exhaust scavenging
- 3" Collector — Optimized for strong low-to-mid RPM torque
- Mandrel Bent Tubing — Consistent tube diameter through every bend; no crimping, no restriction
- CNC Machined Flanges — Precision fit at the head and collector for a leak-free seal
- 304 Natural Stainless Steel Construction — Corrosion resistant, heat tolerant, and built to last
- Longtube Header Design — Maximum scavenging efficiency vs. shorty or mid-length headers
- Standard Graphite Manifold Gaskets Included
- Dyno Proven — 25+ RWHP gain on 5.3L and 6.2L applications
- Compatible with 5.3L and 6.2L V8 Engines
- V8 Engines Only
Vehicle Applications:
Chevrolet Silverado 1500 (2WD/4WD) — 5.3L/6.2L
- 2014 Chevrolet Silverado 1500 (2WD/4WD) — 5.3L/6.2L
- 2015 Chevrolet Silverado 1500 (2WD/4WD) — 5.3L/6.2L
- 2016 Chevrolet Silverado 1500 (2WD/4WD) — 5.3L/6.2L
- 2017 Chevrolet Silverado 1500 (2WD/4WD) — 5.3L/6.2L
- 2018 Chevrolet Silverado 1500 (2WD/4WD) — 5.3L/6.2L
- 2019 Chevrolet Silverado 1500 (2WD/4WD) — 5.3L/6.2L ⚠️ Classic body style only
GMC Sierra 1500 (2WD/4WD) — 5.3L/6.2L
- 2014 GMC Sierra 1500 (2WD/4WD) — 5.3L/6.2L
- 2015 GMC Sierra 1500 (2WD/4WD) — 5.3L/6.2L
- 2016 GMC Sierra 1500 (2WD/4WD) — 5.3L/6.2L
- 2017 GMC Sierra 1500 (2WD/4WD) — 5.3L/6.2L
- 2018 GMC Sierra 1500 (2WD/4WD) — 5.3L/6.2L
- 2019 GMC Sierra 1500 (2WD/4WD) — 5.3L/6.2L ⚠️ Classic body style only
Chevrolet Tahoe (2WD/4WD)
- 2015 Chevrolet Tahoe (2WD/4WD) — 5.3L/6.2L
- 2016 Chevrolet Tahoe (2WD/4WD) — 5.3L/6.2L
- 2017 Chevrolet Tahoe (2WD/4WD) — 5.3L/6.2L
- 2018 Chevrolet Tahoe (2WD/4WD) — 5.3L/6.2L
- 2019 Chevrolet Tahoe (2WD/4WD) — 5.3L/6.2L
- 2020 Chevrolet Tahoe (2WD/4WD) — 5.3L/6.2L
GMC Yukon & Yukon Denali (2WD/4WD)
- 2015 GMC Yukon/Yukon Denali (2WD/4WD) — 5.3L/6.2L
- 2016 GMC Yukon/Yukon Denali (2WD/4WD) — 5.3L/6.2L
- 2017 GMC Yukon/Yukon Denali (2WD/4WD) — 5.3L/6.2L
- 2018 GMC Yukon/Yukon Denali (2WD/4WD) — 5.3L/6.2L
- 2019 GMC Yukon/Yukon Denali (2WD/4WD) — 5.3L/6.2L
- 2020 GMC Yukon/Yukon Denali (2WD/4WD) — 5.3L/6.2L
Cadillac Escalade (2WD/4WD)
- 2015 Cadillac Escalade (2WD/4WD) — 6.2L
- 2016 Cadillac Escalade (2WD/4WD) — 6.2L
- 2017 Cadillac Escalade (2WD/4WD) — 6.2L
- 2018 Cadillac Escalade (2WD/4WD) — 6.2L
- 2019 Cadillac Escalade (2WD/4WD) — 6.2L
- 2020 Cadillac Escalade (2WD/4WD) — 6.2L
FAQ
Do I need O₂ sensor extensions for my truck?
It depends on your model year. 2014–2015 trucks do not require O₂ extensions. 2016–2018 trucks require O₂ extensions. Select the correct option for your model year at checkout to ensure the right kit is included.
Will I get a check engine light after installing this kit?
Yes. The rear downstream O₂ sensors are not used with this system, which will trigger a catalyst efficiency code. This must be resolved through PCM tuning and cannot be cleared by simply resetting the ECU.
What transmissions does the Y-pipe work with?
The Y-pipe is compatible with 6 speed and 8 speed automatic transmissions.
Will this kit fit my 2019 Silverado or Sierra?
Only the 2019 Classic body style. The 2019 model year saw both the outgoing K2XX Classic body and the new T1XX body. This kit fits the K2XX Classic body only. For 2019+ T1XX body style trucks see part 25-1152.
Will this kit fit a 2500 or 3500 with a 6.0L engine?
No. GM 2500/3500 6.0L applications require the 2007–2013 GMT900 exhaust products.
What is included in this kit?
The kit includes a pair of 1-7/8" stainless longtube headers, a 3" off-road Y-pipe, two MLS exhaust gaskets, and zinc-coated header bolts. O₂ extension harnesses are included for 2016–2018 model year trucks — select your year at checkout. An upgrade to stainless ARP bolts is available at checkout. Speed Engineering LS spark plug wires and plug wire fire sleeves can also be added at the time of purchase.
How much horsepower does this kit add?
Speed Engineering's 1-7/8" longtube headers are dyno proven to add over 25 rear-wheel horsepower on 5.3L and 6.2L K2XX applications compared to stock exhaust manifolds.
What material are these headers made from?
304 natural stainless steel with full TIG-welded construction, CNC-machined flanges, and merge spikes.
Are these headers street legal?
No. These are race-only headers intended for closed-course competition use only. Installation on a street-driven vehicle may violate the Clean Air Act (42 U.S.C. 7522(a)(3)).
⚠️ Race Use Only: This product is manufactured and sold for installation on vehicles used solely for competition. Once installed, the vehicle may not be used, registered, or licensed for use on a public road or highway. Installation on a street-driven vehicle may violate the Clean Air Act 203(a)(3), 42 U.S.C. 7522(a)(3).
