Home / Shop / Holley EFI Terminator X LT Main Engine Harnesses 558-129 Wiring Harnesses, EFI, Gen V, Engine, Harness, for X, Max, ECU Only, Chevy, 5.3L, 6.2L, Each

Holley EFI Terminator X LT Main Engine Harnesses 558-129 Wiring Harnesses, EFI, Gen V, Engine, Harness, for X, Max, ECU Only, Chevy, 5.3L, 6.2L, Each

SKU: HLY558-129

Wiring Harnesses

Holley

Holley EFI Terminator X LT Main Engine Harnesses 558-129 Wiring Harnesses, EFI, Gen V, Engine, Harness, for X, Max, ECU Only, Chevy, 5.3L, 6.2L, Each

SKU: HLY558-129

Wiring Harnesses

LOW STOCK! Est Ship 4-7 days. HURRY! LOW STOCK. This item is in limited stock at one of our distribution centres. The ETA is the approximate time required to prepare your order for dispatch.

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Description

Terminator X standalone engine management systems offer performance at a budget price with plug-and-play operation. For use with these ECUs, Holley EFI Terminator X LT main engine harnesses are available to make connecting and servicing your system easier. Choose the one designed for your application.

Part Type

Wiring Harnesses

Data: v4.2 - Upd: 2026-10-13 18:47:12

Specifications

Product Attributes - Brand: Holley
Product Attributes - Manufacturer's Part Number: 558-129
Product Attributes - Part Type: Wiring Harnesses
Product Attributes - Product Line: Holley EFI Terminator X LT Main Engine Harnesses
Product Attributes - UPC: 90127140802
Product Attributes - Harness Length: Standard
Product Attributes - Fuse Block Included: No
Product Attributes - Quantity: Sold individually.
Product Attributes - Notes: This harness is designed for use with Terminator X and X Max ECU's only.

Reference Information

Brand Name/s	Holley
StreetFX SKU	hly558-129
SFX Item ID	4783916
Supplier Item Code	4783916
Manufacturer SKU	558-129
Manufacturer UPC	90127140802
Alternative References	HOL558-129, 5.3L, 6.2L

Compatibility

Application Data

Application Notes	This harness is designed for use with Terminator X and X Max ECU's only.
Beginning Year	2014
Ending Year	2020
Engine Family	CHEVY SMALL BLOCK GEN V V8 GAS
Engine Size	5.3L/325
Engine Type	V8
Make	CHEVROLET
Universal	No

Application Notes	This harness is designed for use with Terminator X and X Max ECU's only.
Beginning Year	2014
Ending Year	2023
Engine Family	CHEVY SMALL BLOCK GEN V V8 GAS
Engine Size	6.2L/376
Engine Type	V8
Make	CHEVROLET
Universal	No

Application Notes	This harness is designed for use with Terminator X and X Max ECU's only.
Beginning Year	2015
Ending Year	2023
Engine Family	CHEVY SMALL BLOCK GEN V V8 GAS
Engine Size	6.2L/376
Engine Type	V8
Make	CHEVROLET
Universal	No

Application Notes	This harness is designed for use with Terminator X and X Max ECU's only.
Beginning Year	2018
Ending Year	2020
Engine Family	CHEVY SMALL BLOCK GEN V V8 GAS
Engine Size	6.2L/376
Engine Type	V8
Make	CHEVROLET
Universal	No

Application Notes	This harness is designed for use with Terminator X and X Max ECU's only.
Beginning Year	2019
Ending Year	2023
Engine Family	CHEVY SMALL BLOCK GEN V V8 GAS
Engine Size	5.3L/325
Engine Type	V8
Make	CHEVROLET
Universal	No

Application Notes	This harness is designed for use with Terminator X and X Max ECU's only.
Beginning Year	2019
Ending Year	2023
Engine Family	CHEVY SMALL BLOCK GEN V V8 GAS
Engine Size	6.2L/376
Engine Type	V8
Make	CHEVROLET
Universal	No

Application Notes	This harness is designed for use with Terminator X and X Max ECU's only.
Beginning Year	2020
Ending Year	2023
Engine Family	CHEVY SMALL BLOCK GEN V V8 GAS
Engine Size	6.2L/376
Engine Type	V8
Make	CHEVROLET
Universal	No

Application Notes	This harness is designed for use with Terminator X and X Max ECU's only.
Beginning Year	2020
Ending Year	2023
Engine Family	CHEVY SMALL BLOCK GEN V V8 GAS
Engine Size	6.6L/401
Engine Type	V8
Make	CHEVROLET
Universal	No

Application Notes	This harness is designed for use with Terminator X and X Max ECU's only.
Beginning Year	2023
Ending Year	2023
Engine Family	CHEVY LT6 V8 GAS
Engine Size	5.5L/333
Engine Type	V8
Make	CHEVROLET
Universal	No

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Holley EFI Terminator X LT Main Engine Harnesses 558-129 Wiring Harnesses, EFI, Gen V, Engine, Harness, for X, Max, ECU Only, Chevy, 5.3L, 6.2L, Each

Holley EFI Terminator X LT Main Engine Harnesses 558-129 Wiring Harnesses, EFI, Gen V, Engine, Harness, for X, Max, ECU Only, Chevy, 5.3L, 6.2L, Each

Description

Part Type

Specifications

Reference Information

Compatibility

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