Re e90 differences:
325d/330d LCI had different injectors
325i/330i LCI had a different intake - http://www.zpost.com/forums/showthread.php?t=455180

Once 330 parts are installed, both diesel and petol LCI 325s could be mapped to 330 levels (or beyond), which makes a lot of sense in Ireland with our punishing CO2 tax regime..