200 MPH face gauge?
 

if i get a new face gauge that goes up to 200MPH and not tha stock 140MPH do i have to change my spidomiter sensor and if so does that come in tha kit

what year mustang do you have? most of the time to have the gauge face you have to have a calibrated 200mph speedometer, so you would have to buy the actual speedometer since they are what is calibrated for the speed. There is a speedometer gear that goes in the trans that has a certain amount of teeth for what axle ratio you have and turns a cable up to the speedometer, so you wouldn't have to change that at all.