{"product_id":"high-output-alternator-for-gmc-sierra-2008-2009-6-6l","title":"High Output Alternator for GMC Sierra (2008-2009) 6.6L","description":"\u003ch2 style=\"font-size: clamp(18px, 3vw, 21px); margin-bottom: 15px; line-height: 1.3;\"\u003eHeavy-Duty 350-Amp High Output Alternator for 2008-2009 GMC Sierra (GMT900)\u003c\/h2\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhat it Does:\u003c\/strong\u003e The 350-Amp High Output Alternator replaces the factory low-amperage charging unit on the 2008-2009 GMC Sierra 6.6L to deliver reliable current capacity for extreme auxiliary electrical loads and eliminate system voltage drops.\u003c\/p\u003e\n\n\u003ch3\u003eThe Stock GMC Sierra Electrical Bottleneck\u003c\/h3\u003e\n\u003cp\u003eFactory charging systems on the \u003cstrong\u003eGMT900\u003c\/strong\u003e platform equipped with the \u003cstrong\u003e6.6L Duramax LMM\u003c\/strong\u003e were engineered with alternators rated at only 125 to 145 amps. When running dual battery banks, high-draw winches, commercial snowplows, high-wattage inverters, or auxiliary lighting, the factory unit suffers from severe thermal saturation. At idle speeds, OEM rectifiers overheat, causing system voltage to sag below 12.8 volts. This induces chronic undercharging, early battery bank degradation, and sensitive ECM sensor erraticism under continuous commercial loads.\u003c\/p\u003e\n\n\u003ch3\u003eThe Engineering Solution\u003c\/h3\u003e\n\u003cp\u003eManufactured in the USA, this 350-amp alternator delivers superior charging stability using heavy-duty copper stator windings, dual internal cooling fans, and high-amperage avalanche diode rectifiers designed to withstand extreme underhood thermal environments. Engineered for bolt-in compatibility with factory accessory brackets, it resolves the load demands of the \u003cstrong\u003e6.6L Duramax LMM\u003c\/strong\u003e without requiring pulley spacers or modifications. It replaces factory assemblies directly, including OEM reference numbers \u003cstrong\u003e8301\u003c\/strong\u003e, \u003cstrong\u003e8301N\u003c\/strong\u003e, \u003cstrong\u003e15093928\u003c\/strong\u003e, \u003cstrong\u003e15857608\u003c\/strong\u003e, \u003cstrong\u003e15095871\u003c\/strong\u003e, \u003cstrong\u003e25877026\u003c\/strong\u003e, and \u003cstrong\u003e8301-350A\u003c\/strong\u003e.\u003c\/p\u003e\n\n\u003ch3\u003eWhat's Included\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003e1x 350-Amp High Output Alternator\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;\"\u003e2008-2009 GMC Sierra 2500HD \/ 3500HD\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;\"\u003e6.6L Duramax Turbo-Diesel (LMM) \/ GMT900\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;\"\u003e365 hp \/ 660 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;\"\u003e8301, 8301N, 15093928, 15857608, 15095871, 25877026, 8301-350A\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\u003e2008 GMC Sierra 2500HD 6.6L V8 Duramax Diesel (LMM)\u003c\/li\u003e\n  \u003cli\u003e2009 GMC Sierra 2500HD 6.6L V8 Duramax Diesel (LMM)\u003c\/li\u003e\n  \u003cli\u003e2008 GMC Sierra 3500HD 6.6L V8 Duramax Diesel (LMM)\u003c\/li\u003e\n  \u003cli\u003e2009 GMC Sierra 3500HD 6.6L V8 Duramax Diesel (LMM)\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 GMT900 Sierra?\u003c\/h4\u003e\n\u003cp\u003eYes, this is a direct fit for the 2008-2009 GMC Sierra equipped with the \u003cstrong\u003e6.6L Duramax LMM\u003c\/strong\u003e turbo-diesel engine.\u003c\/p\u003e\n\n\u003ch4\u003eDo I need to upgrade my main charging cables?\u003c\/h4\u003e\n\u003cp\u003eYes, a heavy-duty 1\/0 AWG \"Big 3\" wiring upgrade is strongly advised to support this unit's 350-amp flow without introducing circuit resistance or heat hazards.\u003c\/p\u003e\n\n\u003ch3\u003eThe GMC Towing Caliber\u003c\/h3\u003e\n\u003cp\u003eHeavy-duty trucks built for severe towing, snow removal, and job-site performance require electrical systems that match their torque. This high-output unit ensures steady 14-volt reserve power under the harshest work conditions.\u003c\/p\u003e","brand":"VelocityMax","offers":[{"title":"Default Title","offer_id":67565646414072,"sku":"DS-E006PVE7R","price":404.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0800\/1290\/2648\/files\/high-output-alternator-for-gmc-sierra-2008-2009-6-6l-1.jpg?v=1791071032","url":"https:\/\/performancechiptuning.com\/de\/products\/high-output-alternator-for-gmc-sierra-2008-2009-6-6l","provider":"Performance Chip Tuning","version":"1.0","type":"link"}