help with electronic modules upgrading m52b25 to m52b28

[dnkx]

i have an e39 with a blown m52 2.5 engine and am considering putting a 2.8 in.

1. if i do this will the 2.8 run on the 2.5's ecu/dme or will i need the ecu/dme from the 2.8 car?

2. if i put the 2.8 ecu/dme in the car will there be any issues? ie is the dme coded to an individual cars vin number, does the dme communicate with the odometer and store mileage, will the mileage tamper light come on, will there be a problem with the immobiliser?

if there is a problem using the 2.8 ecu/dme in the 2.5 car, how is it rectified? is this something that a dealer can correct by plugging the diagnositics in or is it more complicated that that?

also does any one know what these modules full names are (these are the areas that the odo mileage is stored)
1)EWS
2)IKE
3)LCM

thanks inadvance for your help