[Agent_4573]

Yes there is a gear in the speedo. If you get the whole assembly, you could always roll the odometer before putting the assembly in your car so that it read the same amount of miles. If you just bought the overlays, you would also need the matching driven gear for the speedometer. There is also a driver gear in the transmission but you should only need to change that when you change your rear gears. So if you buy the entire gauge cluster from the 90 GT, the 140 speedo will be calibrated for the 90 GT rear gears and will be acurate only if your running those gears. i.e. if the 90gt had 3.73, the speedo will only be acurate if you have 3.73's. Otherwise you will have to buy the driven gear for your trans. You can buy a matching set of speedo gears(driven and driver gear) for about 30 dollars.