The cluster can be reprogrammed, but the tool is $7,200!!! You are going to have to do a couple things, first, get a notorized statement that shows the current mileage and then send it to a shop with the new cluster. Most vehicles can be reprogrammed at the dealer through the OBDII port, but not the newer Fords. The CAN-Bus does most of this, so it can ONLY be programmed from the service port on the cluster. You can also ask the person you are getting it from (if it's a company) if they do the recalibration since MANY speedo shops are selling parts like this. I'm working on the pinouts to fix the LED issues, I'll post a fix soon (I Hope). This is VERY high on my list of mods....
'05 ZX3 ("S") Team Duratec #56
Engine: Modified MBRP Stainless Exhaust, K&N AirCharger, SCT LiveWire (dealer), ScanGauge, poly "dogbone" bushings.
Stereo: '05 Mustang Shaker500 H/U, Polk DB570's and an Infinity BassLink SubWoofer.