D17A2 vtec engine with D16Y8 manifold?

What are the advantages of having a manifold from a D16Y8 into my D17A2 and why are they better than the stock from my D17A2. I have a 2003 honda civic EX coupe and should I swap them?

The d16y8 mani would do a small gain. I heard for the swap you need port or relocate the o2 sensors. AL M you are not answering this poor blokes question! The y8 mani is better because it is not as restrictive as the plastic mani your car comes with. And also be prepared to port and polish, and to fabricate stuff for the manifold swap.

Who said that they are better?
Why do you have a different part for your engine?
Did someone modify your car before you owned it?
It may have been replace with that just because of the part availability, not necessarily for improving performance. Stock manifolds usually performs the same, If performance gain is the purpose then an aftermarket manifold/header would be recommended.