The specific part number of a turbocharger is assigned by the turbo manufacturers within a range of turbochargers. This specific part number can be used to identify the turbocharger straight away, so usually it is recognized as the best form of turbo identification.
There are several manufacturers of turbochargers, which include Garrett, KKK, Borgwarner, Mitsubishi and IHI. Below are guides to help you identify where, in each case, you can find the part numbers which ideally, we require.