[Mr70]

SS454Elky Welcome,
Not a definitive resolution,but take the Tach out.On the back face is a date stamp.Read it to see if it is a possibility.The real ones are dated.
Although the Factory didn't put these in,you could buy these 1971 white face 6500 redline tachs over the parts counter in 1971.
They are reproducing these today,so it can be done,and has been a few years ago in homes,to through confusion into the hobby.
Any Paper on your car at all?
Or what is the plant and time code.I am giving you the benefit of the doubt here,because most would agree it ain't factory. [img]/ubbthreads/images/icons/smile.gif[/img]