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LS and LT Retrofit Specialists
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LS 58x Harness Package (6L80 / 6L90)
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LS 58x Harness Package (6L80 / 6L90)

A harness package for those using an LS 58x engine paired with a 6L80 or 6L90 transmission.

  • Speartech standalone wiring harness with labeled connectors & hook-up wires
  • Programmed ECM
  • ETC Pedal
  • Harness grommet
  • Instructions

Choose your options:
Air Conditioning(required):
MAF Style:
Sending in TCM for reprogramming?(required):
Year/Model of Donor Vehicle(required):
Special Notes(optional):
Add MAF Sensor?:
Add O2 Sensors?:
Add 6L80/90 Tap Shifter?:
Add NSS?:
Cruise Control(optional):
Emissions Wiring(required):
Front End Drive(required):
Examples are Holley, Wegner, CVF Racing, Drive Junky, etc.
6L Reverse CAN relay:
Product Code: 58x6L-HP
This section provides detailed descriptions of the options available to you when ordering a harness. This will follow the "Choose Your Options" area above.

Engine: Select the engine you will be using for your project.

Emissions Wiring: Our harnesses come standard with no emissions wiring (Post CAT O2s, Purge, EVAP, etc.). If your project requires emissions, you can select what you need here. All harnesses come with pre-cat O2 wiring, as these are required for proper operation.

Air Conditioning: If you are planning to use air conditioning with your project, then you want to select "Yes" here. Select "Yes" if using the GM A/C compressor only. When using a Sanden A/C compressor, choose "No". Sanden uses a 1-wire compressor that you tie into your aftermarket A/C system.

MAF Style: This is where you select which MAF you will be using. If you need an LS2 or LS3 MAF sensor, you can add it to your cart below in the "Add MAF Sensor" section.

Determining Your MAF Style

This is the LS2 MAF:

This is the LS3/LS7 MAF:

This is the L92 MAF:

Sending in TCM for reprogramming?: Select yes if you are sending in your T43 TCM for reprogramming. This is necessary if you want the 6L80/6L90 Tap Shift function to work. Click here for instructions on removing your T43 TCM.

Special Notes: This is the area you will want to use to let us know about anything that would be important to us to know when making your harness. Such as which intake manifold you're using if not using the one that comes stock on your engine - like if you're using a car style intake manifold on your truck engine. Or if you're using a "Hi-Ram" style manifold. Anything that may affect connector placement, etc.

Let us know the Year/Make/Model your engine and transmission came from, as well as the Year/Make/Model of the vehicle you are swapping this into.

This is also the place to include any engine modifications (Cam, headers, etc.) as well as your gear ratio and tire size if you are sending in your ECM/TCM for reprogramming. If gear ratio/and or tire size is not known, everything will still operate satisfactorily, but shift points and speedometer may be slightly off. This info helps us program the ECM specific to your vehicle.

If you are sending in your ECM/TCM for reprogramming, just select 'Yes' above and send your item(s) to us and include a copy of your invoice that is emailed to you after you checkout.

Speartech Fuel Injection Systems, Inc.
Attn: Reprogramming
3574 E. State Road 236
Anderson, IN 46017

Add MAF Sensor: You can add the appropriate MAF sensor for your harness here.

Also available - Our complete LSx swap air intake kit.

Includes aluminum tube with MAF bung and screws, elbow and clamps, PCV air tube, and a K&N air filter. A quick and easy way to get your project up and running! More info here. Available with a raw aluminum MAF tube.

Add O2 Sensors: You can add on a pair of the proper front O2s for your harness. Just select "Yes" and we'll include the correct set for your harness!

Add 6L80/90 Tap Shifter?: Here you have the option to add our
floor mounted tap shifter, or our remote mounted tap shift switch box.

Cruise Control: Add this option to have your cruise control system integrated into the harness for plug & play hook up!