i own an 88 stang gt and the previous owner of the car swapped out the gears. i have no idea what is in ther now but it throws my speedo out 10kmph from about 0-50kmph and 20 from 50-120kmph. I would like to no if it is possible to find a speedo tranny gear to help correct the problem. i was told at my local ford dealer that a gear to correct it that much is hard to find. help if ya can