The factory exhaust manifolds on your Pontiac G8 are one of the first restrictions holding back your LS2 or LS3. This complete full kit pairs Speed Engineering's 1-7/8" longtube headers with a 3" off-road X-pipe that connects directly to the existing axle-back location — replacing the restrictive factory exhaust manifolds and mid-pipes with a free-flowing stainless system designed for significant horsepower gains, an aggressive exhaust tone, and long-lasting durability. Dyno proven to deliver over 25 rear-wheel horsepower over stock. Headers are specifically designed to clear the factory oil cooler.
Built from 304 natural stainless steel with mandrel-bent primary tubes, CNC-machined flanges, and full TIG-welded construction.
⚠️ Important Note: Rear downstream O₂ sensors are not used. A check engine light for catalyst efficiency will appear and must be disabled via PCM tuning.
Kit Includes:
- 1 Pair of 1-7/8" Stainless Longtube Headers
- 1 Three-inch Off-Road X-Pipe / Connection Pipe
- 1 Set of Zinc-Coated Header Bolts (upgrade to stainless ARP bolts available at checkout)
- 2 MLS Exhaust Gaskets
- 2 O₂ Sensor Extension Harnesses
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" Port-Matched Primary Tubes — Full-diameter flow from cylinder head to collector for maximum exhaust scavenging
- 3" Collector with Merge Spikes — Optimized merge geometry 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
- Clears Factory Oil Cooler — Engineered specifically for the G8 layout
- Standard Graphite Manifold Gaskets Included
- Dyno Proven — 25+ RWHP gain on G8 applications
- Compatible with 6.0L LS2 and 6.2L LS3 Engines
Vehicle Applications:
Pontiac G8 — LS2/LS3
- 2008 Pontiac G8 — 6.0L LS2
- 2009 Pontiac G8 GT — 6.0L LS2
- 2009 Pontiac G8 GXP — 6.2L LS3
Frequently Asked Questions:
Q: What is the difference between this kit and the 2" G8 header kit? The primary tube diameter is the key difference. The 1-7/8" headers work well across a broad RPM range and are a strong choice for most street and performance G8 builds. The 2" headers offer a step up in flow better suited for more aggressive builds with supporting modifications where maximum exhaust scavenging is the priority.
Q: Which G8 models came with the LS2 and which came with the LS3? The 2008 G8 GT and 2009 G8 GT both came with the 6.0L LS2. The 2009 G8 GXP came with the 6.2L LS3. These headers are compatible with both engines.
Q: 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.
Q: What is included in this kit? The kit includes a pair of 1-7/8" stainless longtube headers, a 3" off-road X-pipe, two MLS exhaust gaskets, two O₂ sensor extension harnesses, and zinc-coated header bolts. 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.
Q: Do these headers clear the factory oil cooler? Yes. These headers are specifically engineered to clear the factory oil cooler on G8 applications.
Q: How much horsepower do these headers add? Speed Engineering's 1-7/8" longtube headers are dyno proven to add over 25 rear-wheel horsepower on Pontiac G8 applications compared to stock exhaust manifolds.
Q: What engines are these headers compatible with? These headers are compatible with the 6.0L LS2 found in the 2008–2009 G8 GT and the 6.2L LS3 found in the 2009 G8 GXP.
Q: What material are these headers made from? 304 natural stainless steel with full TIG-welded construction, CNC-machined flanges, and merge spikes.
Q: 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).
