The factory exhaust manifolds on your GTO are one of the first restrictions holding back your LS1 or LS2. Speed Engineering's 1-7/8" longtube headers are a direct-fit, dyno-proven upgrade that frees up exhaust flow, improves throttle response, and delivers over 25 rear-wheel horsepower over stock.
Built from 304 natural stainless steel with mandrel-bent primary tubes, CNC-machined port-matched flanges, and full TIG-welded construction.
⚠️ Important: Speed Engineering's GTO X-pipe kit is required for proper installation of these headers. The X-pipe is sold separately.
Features:
- Full 1-7/8" Port-Matched Primary Tubes — 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
- Dyno Proven — 25+ RWHP gain on LS1 and LS2 applications
- Compatible with 5.7L LS1 and 6.0L LS2 Engines
Vehicle Applications:
Pontiac GTO — LS1/LS2
- 2004 Pontiac GTO (RWD) — 5.7L LS1
- 2005 Pontiac GTO (RWD) — 6.0L LS2
- 2006 Pontiac GTO (RWD) — 6.0L LS2
FAQ
How much horsepower do these headers add to a Pontiac GTO?
Speed Engineering's 1-7/8" longtube headers are dyno proven to add over 25 rear-wheel horsepower on LS1 and LS2 equipped 2004–2006 Pontiac GTO applications compared to stock exhaust manifolds.
Do I need any additional parts to install these headers?
Yes. Speed Engineering's GTO X-pipe kit is required for proper installation of these headers and is sold separately.
What engines are these headers compatible with?
These headers are compatible with the 5.7L LS1 found in the 2004 GTO and the 6.0L LS2 found in 2005–2006 GTO models.
What size are the primary tubes?
These headers feature full 1-7/8" port-matched primary tubes with a 3" collector.
What material are these headers made from?
304 natural stainless steel with full TIG-welded construction and CNC-machined port-matched flanges.
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).