Gibson GP137S Performance Header - Stainless Steel, 50-State Legal

The Gibson GP137S Performance Header is a stainless steel, direct-fit replacement exhaust header engineered to unlock more usable horsepower and torque at low and mid-range RPM — exactly where you need it most during everyday driving and highway cruising.

Every Gibson Performance Header is dyno-tuned to improve your engine's ability to breathe more efficiently, resulting in better exhaust scavenging, cooler operating temperatures, and a noticeable improvement in overall performance. Designed as a direct replacement for the factory exhaust manifold, this header uses your stock crossover pipe for a straightforward, no-weld installation.

Key Features:

• Dyno-tuned design engineered for maximum low- and mid-range horsepower and torque gains
• Direct OEM replacement — uses factory crossover pipe and OEM-style connections
• 3/8" heavy-duty laser-cut port flanges for a precision fit that resists warping and leaking
• Premium stainless steel construction for superior heat resistance and long-term durability
• Cooler engine operating temperatures through improved exhaust flow efficiency
• Compatible with lowered and raised vehicles — suited for both street and off-road use
• No welding required — bolt-on installation with premium gaskets and hardware included
• 50-State street legal — meets EPA and CARB requirements
• Will not affect factory warranty
• Backed by a Lifetime Limited Warranty

The GP137S ships complete with all necessary premium gaskets and hardware for a clean, professional installation. Whether you're building a street cruiser or a capable off-road rig, this Gibson header delivers real-world performance gains right where you drive.