Replacement instrument cluster Odometer reading

I have a 05 grand prix. If i replace my instrument cluster with a new out of the box unit or from a doner car that has less miles than my GP, will it change my odometer reading to match the doner units milage?

Also, where does the the spedo sensor plug into the tranny? I had a 98 s-10 and it plugged into the passenger side of the tranny.