Holley Wiring Harnesses

Wiring Harnesses, Holley EFI, Main Harness, Unterminated, Flying Lead, 15 ft. Long, J1A/J1B Connectors, Plug Seals Included, Universal, Each

Part Number: HLY-558-126

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Estimated Ship Date: Monday 12/1/2025

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Wiring Harnesses, Holley EFI, LS1/6, 24X/1X, Main Harness, Plug-and-Play, Extended Length, for Dominator/HP EFI Systems, Chevy, 4.8-6.0L, Each

Part Number: HLY-558-133

5.0 out of 5 stars ( 1 )

Estimated Ship Date: Monday 12/1/2025

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Wiring Harnesses, Holley EFI, HyperSpark Ignition Adapter, Plug-and-Play, Holley Main Harness to Terminator X EFI System, Each

Part Number: HLY-558-323

5.0 out of 5 stars ( 1 )

Estimated Ship Date: Monday 12/1/2025

Wire Harnesses, Sniper 2 EFI, Tachometer, Input Ignition, Adapter Harness, for CD Ignition Boxes, Each

Part Number: HLY-558-329

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Estimated Ship Date: Monday 12/1/2025

Wiring Harness Adapters, Sniper EFI 1 Harness to Sniper EFI 2 System, Pre-Terminated, Each

Part Number: SNE-558-489

5.0 out of 5 stars ( 3 )

Estimated Ship Date: Monday 12/1/2025

Wiring Harnesses, Holley EFI, Pro-Billet Ignition Adapter, Plug-and-Play, Holley Main Harness to Terminator X EFI System, Each

Part Number: HLY-558-325

5.0 out of 5 stars ( 1 )

Estimated Ship Date: Monday 12/1/2025

Wire Harnesses, Sniper 2 EFI, Adapter for Pro-Billet Distributer or 2-Wire Magnetic pickup Trigger, Each

Part Number: HLY-558-330

5.0 out of 5 stars ( 2 )

Estimated Ship Date: Monday 12/1/2025

Wiring Harnesses, Holley EFI, LS2/3/7, 58X/4X, Main Harness, Plug-and-Play, Extended Length, for Dominator/HP EFI Systems, Chevy, 6.0-7.0L, Each

Part Number: HLY-558-134

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Estimated Ship Date: Monday 12/1/2025

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Wiring Harnesses, Holley EFI, GM Gen V, GDI Late, Sub-Harness, Direct Injection, Pre-Terminated, 4-pin Fuel Sensor, GM, Late LT Based, Engines, Each

Part Number: HLY-558-221

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Estimated Ship Date: Monday 12/1/2025

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Wiring Harness, Holley EFI, Gen III Hemi, VVT, Sub-Harness Only, Plug-and -Play, for Terminator X, Terminator X Max EFI, Dodge, 5.7L, 6.4L, Each

Part Number: HLY-558-131

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Estimated Ship Date: Monday 12/1/2025

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Wiring Harnesses, Holley EFI, Gen III Hemi, VVT, SRV, Sub-Harness Only, Plug-and -Play, for Terminator X, Terminator X Max EFI, Dodge, 5.7-6.4L, Each

Part Number: HLY-558-132

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Estimated Ship Date: Monday 12/1/2025

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Wiring Harnesses, Holley EFI, Gen V, LT Engine, Main Harness, for Terminator X, Terminator X Max, ECU Only, Chevy, 5.3L, 6.2L, Each

Part Number: HLY-558-129

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Estimated Ship Date: Monday 12/1/2025

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Wiring Harnesses, RetroBright Adapter, H4, Non-Standard Plug, Pin-Out Swap, Plug-and Play, Ceramic, Premium Version,Pair

Part Number: HLY-H820

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Estimated Ship Date: Monday 12/1/2025

Wiring Harnesses, RetroBright, Ground Switched Harness, Easy Installation, Toyota, Land Cruiser, Each

Part Number: HLY-H840

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Estimated Ship Date: Monday 12/1/2025

PIGTAIL HARNESS, HILBORN TPS

Part Number: HLY-EL109-3-HIL

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Estimated Ship Date: Monday 12/1/2025

Wiring Harnesses, Holley EFI, GM Gen V, GDI Early, Sub-Harness, Direct Injection, Pre-Terminated, 4-pin Fuel Sensor, GM, Early LT Based, Engines, Each

Part Number: HLY-558-220

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Estimated Ship Date: Dec 15, 2025 if ordered today

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Wiring Harnesses, RetroBright, Adapter, H4, Non-Standard Plug, Pin-Out Swap, Plastic Version, Entry Level, Pair

Part Number: HLY-H821

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Estimated Ship Date: Monday 12/1/2025

SERVICE HARNESS, STANDALONE PRO DASH

Part Number: HLY-558-457

Not Yet Reviewed

Estimated Ship Date: Dec 15, 2025 if ordered today

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• Special Order