1996 Mercury Tracer Trio Speedometer
 

I have a 96 tracer that the speedometer keeps jumping around on. I did some research and thought it might be the speed sensor. So I replaced that but still have the same issue. I am guessing the only other thing it can be is the speedometer head. I was going to replace it but is there a way to get the mileage to match the actual mileage. Is that something they could or even would do at a dealership. (This is to make it exact same. Not to be fraudulent and change the mileage, thats why I asked if a dealer would do it)

Or are there any other suggestions as to what else this could be. The speedometer cable is not broken. I pulled it out and checked it.