Completely stock harness swap?

You can use the factory harness, but you have to do your homework.

First, I am assuming you already have the 08 motor, if that is the case you need to get a FACTORY service manual for your particular motor. Once you get the service manual you'll need to begin tracing the various circuits.

If at all possible get the engine wiring harness, the under dash wiring harness, the body power harness, and the relay, fuse panel. Using parts of these harnesses you should be able to create a harness that provides the necessary power and sensors so the motor will run correctly.

The benefit of the 545 is that the speed sensors necessary for transmission function are built into the transmission.

The other option is to buy a harness from Hot-Wire or Street and Performance.

This should get you moving in the right direction.

Regards,

Joe Dokes