V-Tec is controlled by the computer, not the head itself. Now there may be a reason why the V-tec switch is at a differant rpm i.e. cam lobe differance, intake manifold, or several other things. If that's the only reason your suggesting the Z6 head I'll probably go with the Y8 just because it cam on newer cars and will therefore have less miles on it.

 

Why do you say that?

The y8 head has been proven to flow better, but it's certainly nothing to write home about.