{"product_id":"high-performance-ignition-coils-for-chevrolet-silverado-1999-2007-4-8l-5-3l-6-0l","title":"High Performance Ignition Coils for Chevrolet Silverado (1999-2007) 4.8L 5.3L 6.0L","description":"\u003ch2\u003eHigh-Output Ignition Coils for 1999-2007 Chevrolet Silverado (Vortec V8 \/ GMT800)\u003c\/h2\u003e\n\n\u003cp\u003e\u003cstrong\u003eReplaces aging, degraded factory coils to restore proper spark energy, eliminate high-RPM misfires, and improve combustion efficiency across all Vortec V8 powerplants.\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003ch3\u003eThe Stock Silverado Ignition Weakness\u003c\/h3\u003e\n\u003cp\u003eThe factory D585 and similar OEM GM ignition coils are notorious for thermal degradation over time. Subjected to extreme under-hood temperatures and constant heat cycling from the cast-iron exhaust manifolds, the internal epoxy potting breaks down, leading to micro-cracks in the coil housing. Once the insulation is compromised, high voltage leaks to the block, causing intermittent misfires, rough idling, hesitation under heavy towing loads, and diminished fuel economy. Additionally, stock blade terminals often corrode due to moisture intrusion, increasing electrical resistance and further weakening the spark output precisely when the LS-based engine demands it most during open-loop acceleration.\u003c\/p\u003e\n\n\u003ch3\u003eThe Engineering Solution\u003c\/h3\u003e\n\u003cp\u003eThese high-performance replacement coils are engineered with upgraded primary and secondary copper windings to deliver a higher voltage output and a faster recharge time (dwell). Encased in a superior high-temperature-resistant epoxy and featuring reinforced oval-shaped female connectors, they completely mitigate the heat soak and cracking issues endemic to the factory units. The precision-machined male terminals ensure minimal voltage drop, translating directly to a stronger, more consistent spark. This direct bolt-on upgrade guarantees optimal burn efficiency, smoothing out the idle, restoring lost low-end torque, and preventing spark blowout under heavy loads or high RPMs.\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;\"\u003e1999-2007 Chevrolet Silverado (4.8L, 5.3L, 6.0L)\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;\"\u003eVortec Gen III \u0026amp; IV (LR4, LM7, LQ4, LQ9) \/ GMT800 \u0026amp; GMT900\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;\"\u003e270-345 hp \/ 285-380 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;\"\u003e920-1020, SKIC121, CUF262, D585, UF262T, 10457730, 12563293, 19005218, 8104577300, EBC1347, IGC0127\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr style=\"background-color: #f9f9f9;\"\u003e\n\u003ctd style=\"padding:8px;\"\u003e\u003cstrong\u003eCoil Type\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding:8px;\"\u003eElectronic Bolt-On\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/table\u003e\n\n\u003ch3\u003eCompatibility\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003e1999-2007 Chevrolet Silverado 1500 (4.8L V8)\u003c\/li\u003e\n  \u003cli\u003e1999-2007 Chevrolet Silverado 1500 (5.3L V8)\u003c\/li\u003e\n  \u003cli\u003e2003-2007 Chevrolet Silverado 1500 (6.0L V8)\u003c\/li\u003e\n  \u003cli\u003e1999-2007 Chevrolet Silverado 2500 \/ 2500 HD (5.3L, 6.0L V8)\u003c\/li\u003e\n  \u003cli\u003e2001-2007 Chevrolet Silverado 3500 (6.0L V8)\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eThe Chevrolet Durability Standard\u003c\/h3\u003e\n\u003cp\u003eWhether you are hauling heavy payloads, towing a fifth wheel, or navigating rugged job sites, dependable ignition is non-negotiable. This upgraded coil pack system ensures your Silverado maintains the rugged reliability and relentless torque the Vortec V8 platform is legendary for.\u003c\/p\u003e","brand":"VelocityMax","offers":[{"title":"Default Title","offer_id":48234270097656,"sku":"DS-EMHX8V6CI","price":149.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0800\/1290\/2648\/files\/Ignition-Chevy-V8.jpg?v=1776103425","url":"https:\/\/performancechiptuning.com\/products\/high-performance-ignition-coils-for-chevrolet-silverado-1999-2007-4-8l-5-3l-6-0l","provider":"Performance Chip Tuning","version":"1.0","type":"link"}