Do it the easy way! You changed from 2.88 to 3.56, and I assume you didn't change tires. divide 3.56 by 2.88 (1.236). Pull your speedo gear, count the number of teeth and multiply by 1.236 and go to Ford and spend 3 bucks on the new gear, pop it in and drive off! So, if you have 15 teeth on the gear you have now (and it was correct at 60 mpoh with the old gears, yes??) go to a Ford dealer and get a gear with 19 teeth (round up to avoid tickets!!). Bada Boom, Bada bing your done (sorry, I just watched The Soprano's!).
