I have a "Custom Rod Gauges" instrument cluster in my '55 Chevy, it was in car when I purchased, so I don't have any instructions. I changed ring gear and pinion and now need to re-calibrate speedometer. Can someone please help me with instructions for re-calibrating this speedometer, or even better if someone could send me a copy of the installation manual with these instructions. I e-mailed the company but no answer. I also called the contact number but got recording that it is no longer a working number. Any help would be greatly appreciated. Thanks, Jim