PPE 116111400 Exhaust Manifolds & Up-Pipes | 2004.5-2005 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax LLY

Features: - Fits 2004.5–2005 6.6L Duramax LLY engines - Cast high-sil moly high-flow exhaust manifolds - Internally sleeved 304 stainless steel up-pipes - Increased inner diameter for better flow - Improves turbo spool-up and throttle response - Reduces exhaust gas temperatures (EGTs) - Increases overall horsepower and torque - Enhances fuel economy and engine efficiency - Designed for maximum durability and reliability - Ideal for towing and performance applications Get The Power Flowing With A Manifold And Up Pipe Combo That Delivers If you’re serious about unlocking real performance from your 2004.5–2005 6.6L Duramax LLY, the PPE Exhaust Manifolds and Up-Pipes are one of the most effective bolt-on upgrades you can make. Designed to free up flow where it matters most, this system helps reduce backpressure, drop exhaust gas temperatures, and give your turbo the boost it needs to spool faster. The result is better throttle response, more pulling power, and a smoother, more efficient ride whether you're daily driving or towing. Crafted from high-sil moly cast manifolds and aircraft-grade stainless steel up-pipes, this setup is made to last and handle heat without warping or cracking. Plus, the larger internal diameter of the up-pipes means you’re getting improved airflow without sacrificing strength or reliability. You’ll notice the difference the first time you step on the throttle. It’s the kind of upgrade that pays off with every mile and turns wasted heat into usable horsepower. Precision Built For Boost Control And Long Term Durability The PPE 116111400 Exhaust Manifolds and Up-Pipes are engineered to optimize exhaust flow for 2004.5–2005 GM 6.6L Duramax LLY engines, helping your turbo operate more efficiently and effectively. The cast manifolds are made from high-sil moly material, chosen for its ability to withstand extreme heat and pressure while maintaining structural integrity over time. The included up-pipes feature internally-sleeved bellows constructed from 304 stainless steel, which resists fatigue and thermal cycling in demanding environments. With an increased internal diameter, these pipes improve the velocity and volume of exhaust flow from the heads to the turbo, helping reduce drive pressure and lower EGTs. The design directly benefits turbo spool-up, allowing quicker boost and smoother transitions under load or acceleration. By improving flow characteristics and reducing restriction, this system contributes to better fuel economy and overall engine performance. Whether you're towing heavy or chasing better throttle response, this upgrade provides long-term reliability backed by PPE’s engineering expertise. It’s built to support both stock and modified power levels with confidence. Fits: 2004.5, 2005 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax LLY Notes: - Designed for 2004.5–2005 GM 6.6L Duramax LLY engines only. - High-flow cast manifolds made from high-sil moly for strength and heat resistance. - Up-pipes feature internally-sleeved bellows for durability under thermal cycling. - Constructed from aircraft-grade 304 stainless steel for long-lasting performance. - Increased internal diameter improves exhaust flow to the turbocharger. - Reduces drive pressure and helps lower exhaust gas temperatures (EGTs). - Accelerates turbo spool-up and improves throttle response. - Designed to enhance power output and fuel efficiency. - Ideal upgrade for towing, performance builds, and high-heat applications.