Could anyone pass along any knowledge about what speedometer can or can not be used with the dash tach. I have a 69 Nova that I am putting a console and gauges. The car did not have the console and gauges originally. I have also purchased a tach gauge for the upper left dash position opposite the clock. After reading some info it looks like a speedometer from a non tach dash will not work properly if I hook up the tach ar visa versa. Or something won't work properly. I want to use the original 69 Nova insturment panel and add the tach in the appropriate place. Help please!