Speedo Calibration

[Amarok]

Hi,

I have finally got my 1997 2.8 Ghia Auto Galaxy on the road, a couple of teething problems but hopefully fixed by the weekend. While the carr was off the road I swapped the dash for a Twin Display one from a Ghia X, along with the control stalks. This has worked OK but the speedo UNDER-READS by 15MPH so when its indicating 30MPH it is actually 45MPH !, I suspect the dash orginally came from a manual. My question is I need to reset the mileometer from 133 to 166 can I also get the speedo recalibrated ??

Regards

Mike