More important than how much a shop will charge is how well a shop does the job. I would ask around for who knows how to install gears properly so they don't howl, whine, or self destruct. Entrusting your car to a shop is not a job you award to the lowest bidder. That being said, labor is anywhere from 250-350 for this job. Also, only use Ford gears, the Ford upgraded install kit, new seals, and Ford friction modifier. LMRS sells a kit with everything for about $260