You need the tachometer, and...that's it. Well, you'll need a couple of screwdrivers to remove the cluster, and then remove the large clock. Basically it's a simple swap with one wire to hook up, and the wire is already existing in your car. Coming off the harness that goes to the instrument cluster, there should be a white/red wire with a spade connector that gets plugged into the back of the tachometer. There are complete instructions on installing a large tach in the archives.