2 Questions on porting LS2 intake manifolds

1) Has anyone done a real good "how-to" and/or a good set of ported intake manifold pics. Even LS1/6 would be good for reference.
2) What are the 3 plastic support pieces in the center? Are they there for flow reasons, or are they actually supports so you don't crush the manifold by leaning on it? Or are they just leftovers from the casting process?
Thanks!

