03 COBRA GAUGES IN 01 COBRA !!!!

[01svt-cobra]

I recently bought a 2003 cobra gauge cluster for my 2001 cobra and the guy I bought it from said that it has 18,000 miles on it, my question is will this new cluster just replace my old one and read the same mileage that is on my car now or have 18,000 miles on it or do I need to reprogram it so where, because I heard that you do because they said my car wont even start with that new gauge cluster in it, and im not really sure and before I start messing with it I want to know how to do it right . THANKS