{"product_id":"exhaust-kit-for-gmc-sierra-1999-2006-4-3l-4-8l-5-3l","title":"Exhaust Kit for GMC Sierra (1999-2006) 4.3L 4.8L 5.3L","description":"\u003ch2 style=\"font-size: clamp(18px, 3vw, 21px); margin-bottom: 15px; line-height: 1.3;\"\u003eHigh-Flow Dual Muffler-Back Exhaust Kit for 1999-2006 GMC Sierra (GMT800)\u003c\/h2\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhat it Does:\u003c\/strong\u003e The dual muffler-back exhaust kit replaces the restrictive factory single tailpipe on the 1999-2006 GMC Sierra \u003cstrong\u003eGMT800\u003c\/strong\u003e to decrease exhaust backpressure and optimize scavenging velocity on \u003cstrong\u003eVortec\u003c\/strong\u003e powerplants.\u003c\/p\u003e\n\n\u003ch3\u003eThe Stock GMC Sierra Exhaust Restriction\u003c\/h3\u003e\n\u003cp\u003eFactory \u003cstrong\u003eGMT800\u003c\/strong\u003e exhaust systems rely on highly baffled, high-impedance single mufflers and crush-bent tailpipes. These standard assemblies induce turbulent boundary layer drag, elevating exhaust gas temperatures (EGTs) and restricting volumetric efficiency under load. Corrosive thermal cycling and moisture accumulation also degrade original aluminized joints over time.\u003c\/p\u003e\n\n\u003ch3\u003eThe Engineering Solution\u003c\/h3\u003e\n\u003cp\u003eThis dual conversion splits flow through a \u003cstrong\u003eFlowsound\u003c\/strong\u003e 2-chamber muffler utilizing a 3-inch inlet and dual 2.5-inch outlets. Paired with 2.5-inch mandrel-bent aluminized steel tailpipes, the system maintains consistent cross-sectional diameter to eliminate internal bottlenecks. The parallel-exit geometry is engineered to route cleanly along the frame rails while maintaining full clearance for OEM receiver hitches and factory-sized spare tires.\u003c\/p\u003e\n\n\u003ch3\u003eWhat's Included\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003e1 Flowsound 2-chamber muffler (single 3\" inlet, dual 2.5\" outlets)\u003c\/li\u003e\n  \u003cli\u003e2 aluminized mandrel-bent two-piece 2.5\" tail pipes (slip-together)\u003c\/li\u003e\n  \u003cli\u003e8 muffler clamps\u003c\/li\u003e\n  \u003cli\u003e1 larger exhaust clamp\u003c\/li\u003e\n  \u003cli\u003e4 rubber-insulated hangers\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eTechnical Specifications\u003c\/h3\u003e\n\u003cdiv style=\"overflow-x: auto; margin-bottom: 20px;\"\u003e\n  \u003ctable width=\"100%\" style=\"border-collapse: collapse; border: 1px solid #e0e0e0; font-size: 14px; min-width: 300px;\"\u003e\n    \u003ctr style=\"background-color: #f9f9f9;\"\u003e\n\u003cth style=\"padding:10px; text-align: left; border: 1px solid #e0e0e0;\"\u003eFitment\u003c\/th\u003e\n\u003ctd style=\"padding:10px; border: 1px solid #e0e0e0;\"\u003e1999-2006 GMC Sierra\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003cth style=\"padding:10px; text-align: left; border: 1px solid #e0e0e0;\"\u003eEngine \/ Chassis\u003c\/th\u003e\n\u003ctd style=\"padding:10px; border: 1px solid #e0e0e0;\"\u003eVortec (LU3, LR4, LM7) \/ GMT800\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr style=\"background-color: #f9f9f9;\"\u003e\n\u003cth style=\"padding:10px; text-align: left; border: 1px solid #e0e0e0;\"\u003eStock Output\u003c\/th\u003e\n\u003ctd style=\"padding:10px; border: 1px solid #e0e0e0;\"\u003e200–295 hp \/ 260–335 lb-ft\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003cth style=\"padding:10px; text-align: left; border: 1px solid #e0e0e0;\"\u003eReplaces OEM Part #\u003c\/th\u003e\n\u003ctd style=\"padding:10px; border: 1px solid #e0e0e0;\"\u003eN\/A\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003c\/table\u003e\n\u003c\/div\u003e\n\n\u003ch3\u003eCompatibility\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003e1999-2006 GMC Sierra 1500 \/ 2500 with 4.3L V6, 4.8L V8, or 5.3L V8 gasoline engines\u003c\/li\u003e\n  \u003cli\u003eFits all wheelbases\u003c\/li\u003e\n  \u003cli\u003eOnly compatible with configurations originally equipped with a factory single-inlet muffler\u003c\/li\u003e\n  \u003cli\u003eExcludes diesel platforms and factory dual-inlet muffler configurations\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eFrequently Asked Questions \u0026amp; Fitment Warnings\u003c\/h3\u003e\n\u003ch4\u003eDoes this fit the GMT800 Sierra?\u003c\/h4\u003e\n\u003cp\u003eYes, this fits the 1999-2006 GMC Sierra \u003cstrong\u003eGMT800\u003c\/strong\u003e equipped with \u003cstrong\u003eVortec 4300\u003c\/strong\u003e, \u003cstrong\u003eVortec 4800\u003c\/strong\u003e, or \u003cstrong\u003eVortec 5300\u003c\/strong\u003e engines, excluding models that came from the factory with dual-inlet mufflers.\u003c\/p\u003e\n\n\u003ch4\u003eIs this kit a direct bolt-on installation?\u003c\/h4\u003e\n\u003cp\u003eNo, this is not a direct bolt-on kit; an experienced installer may need to cut or fabricate adapter sections, and exhaust tips are not included.\u003c\/p\u003e\n\n\u003ch3\u003eThe GMC Sierra Towing Standard\u003c\/h3\u003e\n\u003cp\u003eBuilt to handle severe duty cycles and aggressive payload demands, this system provides durable aluminized corrosion resistance and low-restriction gas evacuation that keeps your \u003cstrong\u003eGMT800\u003c\/strong\u003e performing under heavy towing loads.\u003c\/p\u003e","brand":"VelocityMax","offers":[{"title":"Default Title","offer_id":67562629660920,"sku":"DS-EB2HGYGFL","price":229.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0800\/1290\/2648\/files\/exhaust-kit-for-gmc-sierra-1999-2006-4-3l-4-8l-5-3l-1.jpg?v=1790987529","url":"https:\/\/performancechiptuning.com\/fr\/products\/exhaust-kit-for-gmc-sierra-1999-2006-4-3l-4-8l-5-3l","provider":"Performance Chip Tuning","version":"1.0","type":"link"}