2002 Local E39 M54 engined changed from 8-character (digit+alphabet) to 13-digits

[zib]

Hi all,I am about to buy the above car but just found out that the engine has been changed sometime last year. the original engine number was 6914M920 but now changed to 13 numeric only code.But it has been endorsed by JPJ nonetheless with the same capacity. Wonder what is the difference between the number with alphabet vs teh 13-digits type? Thanks for any advice and tips. Anything I should avoid here?Cheers