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Speedway 1999-2003 Vortec V8 Wiring Harness, Extended
Speedway 1999-2003 Vortec V8 Wiring Harness, Extended

Speedway 1999-2003 Vortec V8 Wiring Harness, Extended

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Speedway 1999-2003 Vortec V8 Wiring Harness, Extended
Speedway 1999-2003 Vortec V8 Wiring Harness, Extended
Speedway 1999-2003 Vortec V8 Wiring Harness, Extended
Speedway 1999-2003 Vortec V8 Wiring Harness, Extended
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Part # 91099034
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Four foot extended length, for mechanical throttle.


Take the fear out of electronic fuel injection! These engine wiring harnesses are designed to make your engine transplant effortless. Each new harness contains in-depth application-specific instruction sheets, clearly marked factory GM connectors, labeled GXL jacketed wire, GM color coding, and pre-fitted corrugated slit loom for an extra value and professional look. All un-needed emissions wiring is eliminated to make the install as simple and reliable as possible.

1999-2003 Vortec V8 - Cable Throttle Body

  • Made from premium grade GXL jacketed automotive wire
  • Most wiring is larger gauge than stock application for durability
  • No splices to reduce points of failure
  • All primary grounding is done at the head or block and grounding points are isolated from each other to reduce electrical interference and minimize ground looping
  • Harness wiring matches GM wiring configuration and jacket colors follow GM color coding for easy identification
  • All electrical connectors are made by Delphi or Packard and are direct fit for GM cars and trucks
  • Can be installed to run engine in 20 minutes, but figure 4-6 hours for a professional installation
  • Diagnostic connector or OBD2 port for connection to scanners and tuning tools
  • Made in the USA.


  1. This harness is made with 4L60E connections included and is easily modified for 4L80E. Also has speed sensor wiring. ECM programming will need to match transmission style. 
  2. Common aftermarket fuel pump relay is included. Fan relay is not included since the '99-'03 trucks had mechanical fans, however there are fan relay trigger wires included in the break out.
  3. These harnesses feature all of the connection points necessary to run the engine and transmission if applicable. The emission equipment has been eliminated and only the needed connections to run the engine and transmission are incorporated.
  4. ECM programming will need to be done to remove all of the unneeded trouble codes that may be active from the stock application. Programming will need to be done to remove VATS (vehicle anti-theft system) programming, otherwise the engine will not run. These wiring harnesses do not include any type of VATS module to defeat the theft system.
  5. Standard length harnesses are 54" from the back of the engine to the PCM connectors. Extended length harrnesses add an extra 4 ft. to remote-mount the PCM in your glovebox or underneath your dash.


This harness is covered under warranty for the lifetime of the original owner against defects in workmanship within the wiring harness only, not time, or any damage in result of defective workmanship of the wiring.

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  • Get FREE shipping when your order includes this item and exceeds $99! Ground shipping only in the contiguous US.
Some parts are not legal for use in California or other states with similar laws/regulations

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