{"product_id":"sierra-18-5484-1-electronic-distributor-for-gm-v8-marine-engines-262-454-502-delco-est-direct-replacement","title":"Sierra 18-5484-1 Electronic Distributor (Late HEI), Replaces 3857449, Conventional Rotation V8 262-454 \u0026 502","description":"\u003cp\u003eThe Sierra 18-5484-1 Electronic Distributor is a Late HEI style ignition distributor engineered as a plug-in replacement for GM-style EST ignition system distributors used in marine V8 engine applications. It is built for conventional rotation V8\/LH 262-454 \u0026amp; 502 engines, except 348\/409 and tall block engines. At the core of the distributor is the Ignitor II ignition module with adaptive dwell control, which adjusts spark timing across the entire RPM range to help maximize engine performance and maintain consistent, reliable ignition output.\u003c\/p\u003e\u003cp\u003eInternally, the distributor uses an upper roller bearing paired with an oil impregnated bronze sintered bottom bushing, aligned and bored for accuracy to deliver maximum durability under marine operating conditions. A machined, heat treated gear is manufactured to tight tolerances to ensure long-term durability and consistent timing. The steel gear is compatible with both flat tappet and hydraulic roller cams, giving it broad application across GM-based marine V8 setups. The housing is of aluminum construction, and the distributor combines a ball bearing and bushing setup for maximum timing stability and long service life.\u003c\/p\u003e\u003cp\u003eThe unit features a reliable, high signal strength trigger system and is built to meet or exceed SAE J1171 standards, the marine ignition protection standard. A companion Sierra 18-5281 tune-up kit is available for maintenance of this distributor. As with other Sierra ignition components, this distributor is engineered to meet the demands of high horsepower marine engines while standing up to the harsh marine environment, and it meets or exceeds the performance of the original equipment part it replaces.\u003c\/p\u003e\u003ch3\u003eSpecifications\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eBrand:\u003c\/strong\u003e Sierra\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eManufacturer Part Number:\u003c\/strong\u003e 18-5484-1\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eProduct Type:\u003c\/strong\u003e Electronic Distributor (Late HEI)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eRotation:\u003c\/strong\u003e Conventional Rotation\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFitment:\u003c\/strong\u003e V8\/LH 262-454 \u0026amp; 502 (Except 348\/409 and Tall Block Engines)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eIgnition Module:\u003c\/strong\u003e Ignitor II with adaptive dwell control\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eBearing Type:\u003c\/strong\u003e Upper roller bearing and oil impregnated bronze sintered bottom bushing\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eGear Material:\u003c\/strong\u003e Machined, heat treated gear\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eGear Compatibility:\u003c\/strong\u003e Flat tappet or hydraulic roller cams\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eHousing Material:\u003c\/strong\u003e Aluminum\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eStandard Compliance:\u003c\/strong\u003e Meets or exceeds SAE J1171\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCompatible Tune-Up Kit:\u003c\/strong\u003e Sierra 18-5281\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight:\u003c\/strong\u003e 2.99 pounds\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eProduct Dimensions:\u003c\/strong\u003e 0.39 x 0.39 x 0.39 inches\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFitment\u003c\/h3\u003e\u003cul\u003e\u003cli\u003eConventional Rotation V8\/LH 262-454 \u0026amp; 502 (Except 348\/409 and Tall Block Engines)\u003c\/li\u003e\u003c\/ul\u003e\u003ch3\u003eReplaces (OEM)\u003c\/h3\u003e\u003cul\u003e\u003cli\u003e3857449\u003c\/li\u003e\u003c\/ul\u003e\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eWhat engines does the Sierra 18-5484-1 distributor fit?\u003c\/strong\u003e The Sierra 18-5484-1 Electronic Distributor is designed for conventional rotation V8\/LH 262-454 \u0026amp; 502 engines, except 348\/409 and tall block engines.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes the 18-5484-1 replace an OEM distributor?\u003c\/strong\u003e Yes, the 18-5484-1 replaces OEM number 3857449 and is designed as a plug-in replacement for the GM-style EST ignition system distributor.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat ignition module is used in this distributor?\u003c\/strong\u003e The Sierra 18-5484-1 uses the Ignitor II ignition module with adaptive dwell control, which adjusts spark timing across the entire RPM range to maximize performance.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is the housing material on the 18-5484-1 distributor?\u003c\/strong\u003e The housing is constructed of aluminum, paired with a ball bearing and bushing combination for maximum timing stability and long service life.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs the gear on the 18-5484-1 compatible with roller cams?\u003c\/strong\u003e The steel gear on the Sierra 18-5484-1 distributor is compatible with either flat tappet or hydraulic roller cams.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow much does the Sierra 18-5484-1 distributor weigh?\u003c\/strong\u003e The Sierra 18-5484-1 Electronic Distributor weighs 2.99 pounds.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat bearing setup does this distributor use for durability?\u003c\/strong\u003e An upper roller bearing and an oil impregnated bronze sintered bottom bushing are installed and aligned bored for accuracy, providing maximum durability in the 18-5484-1 distributor.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes the 18-5484-1 distributor meet marine ignition standards?\u003c\/strong\u003e Yes, the Sierra 18-5484-1 distributor meets or exceeds SAE J1171 standards for marine ignition protection.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs there a tune-up kit available for the 18-5484-1 distributor?\u003c\/strong\u003e Sierra offers tune-up kit 18-5281 as a companion part for servicing the 18-5484-1 Electronic Distributor.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow does the 18-5484-1 compare to the original equipment distributor it replaces?\u003c\/strong\u003e The Sierra 18-5484-1 is engineered to meet or exceed the performance of the original equipment distributor it replaces, in this case OEM number 3857449.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat kind of trigger system does the 18-5484-1 use?\u003c\/strong\u003e The Sierra 18-5484-1 distributor features a reliable, high signal strength trigger system as part of its Late HEI design.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat are the dimensions of the Sierra 18-5484-1 distributor?\u003c\/strong\u003e The Sierra 18-5484-1 Electronic Distributor measures 0.39 x 0.39 x 0.39 inches.\u003c\/p\u003e","brand":"Sierra","offers":[{"title":"Default Title","offer_id":48988218163419,"sku":"SIE-18-5484-1","price":617.84,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0839\/7586\/4539\/files\/SIE-18-5484-1__86956.1753385267.500.750.jpg?v=1785188801","url":"https:\/\/www.goodvibesmarina.com\/products\/sierra-18-5484-1-electronic-distributor-for-gm-v8-marine-engines-262-454-502-delco-est-direct-replacement","provider":"Good Vibes Marina","version":"1.0","type":"link"}