Intake Manifold questions...?

[Killa_CRX]

Does anyone have any performance charts on the differences between the D16Y7, D16Y8, and D16Z6 intake manifolds?

Would there be any performance gain if say, I used a D16Z6 intake manifold instead of my D16Y7 intake manifold.. or even the D16Y8 manifold?

[itechengineers]

I cant supply charts or diagrams but i've heard the y8 intake manifold is the best yet for a z6 head and it does make a difference. = that could be a rumor.