97+ xj gauge cluster question

i tried searching but couldn't find any deffinate awnsers

my girlfriends jeep is the SE modle meaning it has basicly no options

and one of the things that drives me crazy about it is it doesn't have a tach but i have a gauge cluster from my old 2000 xj that i parted out

now i know that the gauge cluster are interchangeable but what i'm wondering about is will the millage change because my GF's jeep has 40K on it and the other one has 115K and i rather not have to try to explain that if she were to want to sell it. i know some people on here have done this i just dont wanna rip everyhting apart and then be pissed because here jeep now appears to have 115K instead of 40K

thanks,
-Dylan

PS: her jeep is a 97' even though that shouldn't matter

I did this upgrade...you can have the cluster reprogrammed to the right mileage at dealer or there are independant people out there that can do it for a price.

You can also google it...I think there is a place where you can fedex your cluster to them and they can reprogram it for you...quick turn around using fedex.

Just did a quick search and found these guys:
http://www.prospeedo.com/
http://www.speedofix.com/

By the way, mine was reprogrammed by a local shop when I was living in California...guy picked it up at my work place...had it done at the end of the day.