I'm a little confused about which gear to use because 5.0resto.com lists different gears for different years. For 83-89 cars they say you need the black 20 tooth, but 90-98s need the white 23 tooth. But I have a TKO which didnt come in either of those cars so which one do I need.
according to Ford, you need a black one 20 teeth. This is based on a speedo drive gear of 7 teeth which is yellow. If you have an 8 teeth drive gear you would need a 23 teeth designed for 8 teeth drive gears. Ford number M-17271-C