99- GM P/U 4.8/5.3L S.S. Header

The Gibson Exhaust 99-GM P/U 4.8/5.3L Stainless Steel Header (Model GP115S) is a bolt-on performance upgrade designed specifically for 1999–2001 Chevrolet and GMC full-size trucks and SUVs equipped with small block engines. This shorty header replaces the restrictive factory exhaust manifolds with mandrel-bent primary tubes and a stainless steel construction, freeing up horsepower and torque while delivering a more aggressive exhaust tone.

The header features 1.625-inch primary tubes that optimize scavenging efficiency for 4.8L and 5.3L displacement engines, balancing backpressure and flow across the RPM range. The stock collector flange design ensures direct fitment to factory exhaust systems without modification, making this a bolt-on installation for most users. Supplied as a pair with gaskets and mounting hardware, the all-stainless construction resists rust and corrosion even in harsh conditions, maintaining durability and appearance over years of service. At 19.6 lbs, the lightweight design minimizes unsprung weight without sacrificing structural integrity.

This header serves truck owners and SUV enthusiasts seeking measurable performance gains without a full exhaust system overhaul. Whether upgrading an aging Silverado, Sierra, Suburban, or Tahoe, the GP115S delivers improved throttle response, better mid-range power, and enhanced engine efficiency. Shorty headers are popular in the GM truck community because they clear typical aftermarket accessories and suspension modifications while maintaining factory underbody clearance—ideal for vehicles that balance street duty with occasional towing or off-road use.

Gibson Exhaust headers are engineered to OEM specifications and widely recognized in the small-block Chevrolet market for consistent fitment and durability. The stainless steel finish delivers both longevity and a professional appearance, making this an upgrade that improves function and aesthetics for serious truck builders and daily drivers alike.