The reason we have a different part number is:
We have to declare the part numbers early on in the homologation process whilst we have not yet tested emissions or Noise in the local market.
If any changes are required that are market specific then its not possible to change just for the market without a separate part number.
In the case of LS – we were able to use a std tune from another market.
So therefore we have two top level part numbers using the same calibration.