4L60E to 4L80E Transmission Adapter Harness — Manufacturer part number: 31-1010.

Speed Engineering 4L60E to 4L80E Transmission Adapter Harness kit allows you to convert your existing 4l60e transmission to a 4l80e transmission. This harness is compatible with 1998-2002 Camaro/Firebird, GTO, and all GM trucks and SUV’s from 1996 to 2006. There are two separate components of the conversion harness. The first is the adapter harness that converts your current transmission plug and wires to the new 80e configuration. This saves you the trouble of repining any connectors. The second component is the Input Speed Sensor connector. This part of the conversion harness runs from the FRONT ISS sensor on the transmission to the ECM. This will give the ECM the correct signal it needs to operate the transmission. In order to complete the conversion you will also have to have the ECM flashed with the correct calibration changes for the 80e transmission.
 

Features include:

• 11 pin Transmission Harness
  
• VSS Harness
• Braided cable loom

Note: Depending on our harness, Orange wire goes to Pin 22 and Blue wire goes to Pin 23 on VSS harness. If harness is blue & red wires, Blue wire goes to Pin 22 and Red wire goes to Pin 23 on VSS harness

Note: Only works on 1999-2006 GM Trucks & SUVs for swap conversion. Does not work on 2007+ applications.

(Warning) This is a RACE ONLY product manufactured and sold for installation on vehicles to be used solely for competition purposes. Once this part is installed, the vehicle may never be used, or registered or licensed for use, on a public road or highway. If you install this part on your vehicle and use the vehicle on a public road or highway, you will violate the Clean Air Act 203(a)(3), 42 U.S.C, 7522(a)(3) and may be subject to personal civil or criminal liability.

Fitment and ordering

Confirm the vehicle, engine, dimensions and application restrictions listed above before ordering. Speed Engineering parts are designed to work with Speed Engineering components; mixing brands may require modifications.

Manufacturer specifications and availability checked October 4, 2026. Availability refers to the manufacturer and can change; it does not indicate stock held at Speedzone.

Returns: All Speed Engineering product sales are final. No returns are accepted on Speed Engineering products. Please verify fitment before ordering. See our Return Policy for additional terms. This does not limit any consumer rights that cannot be waived under applicable law.