Hi I'd say that the tach is 100/6 as well. I think you'll have to measure it once again, and you will find that it is 4 inches, not 5 inches. Per Herbert Miller skrev den 2015-04-22 20:55: > > 2.I have a 5 inch gold faced tack. The red line is at 4800. What Healey > had a red line of 4800, or is this tack for a different car? >