21 Remember the DIP switches we showed you earlier? Well, those will be used to adjust the speedo. Using a GPS, we took the car out and ran it up to 60 mph. With the GPS reading 60 mph, we looked at what the speedo was reading. Lucky for us it was reading 60 so we were good. But if it was giving a different speed, let’s say 65 mph, it’s an easy fix. We would have to go and place the number 4, 7 and 10 switches into the open position. There are 80 different switch combinations to contend with readings from 41 to 119 mph to bring you back to a 60-mph reading. Our gauges work perfectly. The needles sweep nice and smooth, the fuel gauge was dead on, and the LED lighting really lets them shine at night. Now we can throw out the extra gauges we have hanging from the dash and take advantage of the Classic Instruments cluster.