CX has 4 Airbus A330-300 aircrafts installed with the new Business Class and it is coded "333" as these aircrafts feature 3 class cabins and hence the letter 3 at the end.

I haven't come across the 747-400 aircraft code yet but I would imagine that they would code it "74C".

The new Business Class product is a superb product with innovative new features, wider and longer seats to stretch out, AVOD system, inflight email and intranet, The Bar and Private Dressing Room. You are in for a treat when you fly CX's new J class.