Here we have a good used engine wiring harness removed from a 2003 GMC 2500hd with the 6.6 Duramax, Allison transmission and electric shift transfer case. This is the harness that sit right on the engine and plugs into the injectors, not the one that runs around the engine and down to the transmission. This harness was removed from a running and driving truck and is in useable condition but may have cosmetic deficiencies on the wires and/or plug ends but I'm sure it will work just fine in your truck to. This will fit 03-04 trucks and probably even 01-02 trucks with the LB7 engine but please compare it to your existing harness plugs to ensure its the one you need, these are non returnable. if you need any parts just inquire.