im not sure if there is more than one type of vvt engine but i do know that there are diffrent variations of the engine.
I've got a vvt engine in my 98 b4 (jap import) and the spare engine i have for it has 4 cam sensors fitted (not sure of the year but was from the uk vvt b4) to it where as the engine in the bike only has one sensor I hav'nt found any other diffrences
I think VC stands for Valve Control or Variable Cam one or the other.
Andy