{"product_id":"performance-headers-manifolds-chevrolet-silverado-gmc-sierra-2001-2016-duramax-6-6l-diesel","title":"Performance Headers Manifolds Chevrolet Silverado GMC Sierra (2001-2016) Duramax 6.6L Diesel","description":"\u003ch2\u003eHigh-Flow Performance Exhaust Manifolds for 2001-2016 (6.6L Duramax)\u003c\/h2\u003e\n\u003cp\u003e\u003cstrong\u003eDesigned to reduce exhaust gas temperatures (EGTs) and lower drive pressure, these stainless steel exhaust manifolds replace restrictive factory cast units to accelerate turbo spool-up and increase total airflow by up to 55 percent.\u003c\/strong\u003e\u003c\/p\u003e\n\u003ch3\u003eThe Stock Silverado \u0026amp; Sierra Restriction\u003c\/h3\u003e\n\u003cp\u003eThe factory cast iron exhaust manifolds on the 6.6L Duramax suffer from severe internal bottlenecks, specifically on the driver side where the cast design pinches down to clear steering components. This restricts exhaust volume and creates unequal exhaust gas distribution before reaching the up-pipes. Under heavy towing or tuned conditions, this restriction causes a sharp spike in drive pressure and elevates EGT levels. Furthermore, the OEM cast iron is highly prone to heat cycling fatigue, often leading to cracked walls, warped mounting flanges, and blown exhaust gaskets that bleed off the critical drive pressure required for efficient turbo operation.\u003c\/p\u003e\n\u003ch3\u003eThe Engineering Solution\u003c\/h3\u003e\n\u003cp\u003eThese upgraded manifolds are manufactured from thick-walled stainless steel to resist the extreme thermal expansion and contraction cycles typical of heavy hauling applications. By redesigning the internal runner geometries and expanding the overall cross-sectional area, these headers yield up to a 55% increase in volumetric airflow over the stock cast units. This balanced flow equalizes cylinder bank pressures, driving the turbine wheel with greater kinetic energy to measurably reduce turbo lag. The resulting drop in exhaust backpressure lowers sustained EGTs during high-load scenarios, safeguarding internal engine components while freeing up usable torque. The kit includes fresh multi-layer steel (MLS) gaskets for reliable installation, engineered to integrate perfectly with OEM-length up-pipes.\u003c\/p\u003e\n\u003ch3\u003eTechnical Specifications\u003c\/h3\u003e\n\u003ctable width=\"100%\" style=\"border-collapse: collapse; border: 1px solid #e0e0e0; font-size: 14px;\"\u003e\n\u003ctbody\u003e\n\u003ctr style=\"background-color: #f9f9f9;\"\u003e\n\u003ctd style=\"padding: 8px;\"\u003e\u003cstrong\u003eFitment\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 8px;\"\u003e2001-2016 GMC, Chevrolet Silverado, Sierra\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 8px;\"\u003e\u003cstrong\u003eEngine \/ Chassis\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 8px;\"\u003eLB7, LLY, LBZ, LMM, LML \/ GMT800, GMT900, K2XX\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #f9f9f9;\"\u003e\n\u003ctd style=\"padding: 8px;\"\u003e\u003cstrong\u003eStock Output\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 8px;\"\u003e300-397 hp \/ 520-765 lb-ft (Approx)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 8px;\"\u003e\u003cstrong\u003ePart Number\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 8px;\"\u003eN\/A\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003ch3\u003eCompatibility\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e2001-2016 GMC Sierra 2500\/3500 6.6L Duramax Diesel\u003c\/li\u003e\n\u003cli\u003e2001-2016 Chevrolet Silverado 2500\/3500 6.6L Duramax Diesel\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFitment Note:\u003c\/strong\u003e These exhaust manifolds will ONLY work with OEM length up pipes!\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eThe Heavy-Duty Standard\u003c\/h3\u003e\n\u003cp\u003eBuilt to endure continuous high-load towing and grueling thermal stress, these manifolds restore necessary reliability to your Duramax platform. By providing essential EGT management and structural longevity, this upgrade ensures your heavy-duty rig maintains peak pulling power without the risk of blown gaskets or cracked castings.\u003c\/p\u003e","brand":"VelocityMax","offers":[{"title":"Default Title","offer_id":48269305413880,"sku":"DS-EOM4KO87Z","price":409.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0800\/1290\/2648\/files\/performance-headers-manifolds-chevrolet-silverado-gmc-sierra-2001-2016-duramax-6-6l-diesel-1.webp?v=1776897098","url":"https:\/\/performancechiptuning.com\/fr\/products\/performance-headers-manifolds-chevrolet-silverado-gmc-sierra-2001-2016-duramax-6-6l-diesel","provider":"Performance Chip Tuning","version":"1.0","type":"link"}