:dunno:
The inside of the D16Y8 manifold doesn't look like anything special to me. It actually looks pretty rough, so I don't think it'd flow any better than a D16Z6 manifold. As for the fuel rail and injectors, the Y8 rail has the FPR on the opposite side I believe, so you would probably need to extend your return line, but like the manifold, I doubt it flows any better than a Z6 rail. As for the injectors, they're 240cc like most other Honda injectors(including the Z6's), but they're OBD-II, which means the clips are different from the Z6 injectors clips(OBD-I). If you're looking for Y8 parts that'll give you a little more power, look for a Y8 head. The Y8 head has a square combustion chamber and yields slightly higher compression than the Z6, and I also think it flows a little better. This is most of the reason why Y8's are rated at 127hp and Z6's are rated at 125.