{"product_id":"ignition-coil-iridium-spark-plugs-wire-for-chevrolet-trailblazer-ext-2003-2004-5-3l","title":"Ignition Coil \u0026 Iridium Spark Plugs \u0026 Wire for Chevrolet Trailblazer EXT (2003-2004) 5.3L","description":"\u003ch2\u003eHigh-Output Ignition Coil, Wire \u0026amp; Iridium Spark Plug Kit for 2003-2004 Chevrolet Trailblazer\u003c\/h2\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhat it Does:\u003c\/strong\u003e Completely renews primary and secondary ignition delivery on the 5.3L V8 to restore lost engine combustion efficiency, smooth idle stability, and eliminate load-induced misfires.\u003c\/p\u003e\n\n\u003ch3\u003eThe Stock Trailblazer Thermal Breakdown\u003c\/h3\u003e\n\u003cp\u003eUnder heavy towing and extended thermal cycling in the confined GMT370 engine bay, factory round coils and carbon-core wires experience severe dielectric fatigue. Internal primary and secondary windings develop micro-fractures, while factory silicone boots harden and leak high-voltage energy to ground. Concurrently, factory wire resistance climbs, degrading secondary voltage delivery and causing spark blowout, erratic idle, and catalytic-damaging unburnt fuel wash.\u003c\/p\u003e\n\n\u003ch3\u003eThe Engineering Solution\u003c\/h3\u003e\n\u003cp\u003eThis comprehensive service package replaces degraded components with round UF262\/D585-style coils potted in high-grade dielectric epoxy to eliminate internal arc bridging. Paired with 8mm stranded-copper core silicone wires featuring stainless-steel heat-shield terminals, this assembly withstands exhaust manifold radiant heat without resistance spike. Fine-wire iridium spark plugs drop voltage requirements while delivering a concentrated spark kernel for complete combustion under full throttle load.\u003c\/p\u003e\n\n\u003ch3\u003eTechnical Specifications\u003c\/h3\u003e\n\u003ctable width=\"100%\" style=\"border-collapse: collapse; border: 1px solid #e0e0e0; font-size: 14px;\"\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;\"\u003e2003-2004 Chevrolet Trailblazer EXT\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;\"\u003e5.3L Vortec LM4 V8 \/ GMT370\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;\"\u003e290 hp \/ 325 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;\"\u003eUF262, D585, 41-962, 19299585, 12192195\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/table\u003e\n\n\u003ch3\u003eCompatibility\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003e2003-2004 Chevrolet Trailblazer EXT (5.3L V8 LM4 Vortec)\u003c\/li\u003e\n  \u003cli\u003eDirect interchange with round coil OE references: UF262, D585, C1251, 10457730, 12563293, 12573190, 8104577300, 8125731900, GN10119, 5C1082, E254, E254P, 52-1647, IC413, 6737101, 19005218\u003c\/li\u003e\n  \u003cli\u003eWire cross references: 12192195, 9748GG, 748GG, 748UU, 12622553, 88862397, 12656210, XS10388, 12192192, 7873\u003c\/li\u003e\n  \u003cli\u003eSpark plug cross references: 19299585, 41-962\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eThe Chevrolet Heavy-Duty Caliber\u003c\/h3\u003e\n\u003cp\u003eEngineered to handle the continuous payload and towing demands of the extended GMT370 platform, this ignition system delivers uncompromising spark consistency through steep grades and sustained high-RPM operation.\u003c\/p\u003e","brand":"VelocityMax","offers":[{"title":"Default Title","offer_id":50498309554424,"sku":"DS-E7ID66F5B","price":185.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0800\/1290\/2648\/files\/ignition-coil-iridium-spark-plugs-wire-for-chevrolet-trailblazer-ext-2003-2004-5-3l-1.jpg?v=1789266052","url":"https:\/\/performancechiptuning.com\/products\/ignition-coil-iridium-spark-plugs-wire-for-chevrolet-trailblazer-ext-2003-2004-5-3l","provider":"Performance Chip Tuning","version":"1.0","type":"link"}