Can someone tell me how I can fix my Tach and Speedometer? My Tach looks like it is not even working when I **** a gear. It drops all the way to the bottom and it hesitates then jumps back up to what I think is the proper RPMS. Also my Speedometer is off by I think 8 miles an hour e.g....Speedo says i'm going 55 and friend calls me up that is in his car right beside me says I am going 63. How can I set my Speedo right? Oh ya my tires are the factory size on them 185/65/14