Possible differences engine wise from evo:

-smaller turbo
-smaller intercooler
-smaller exhaust diameter
-less aggressive tune
-less psi (12-14?)
-cast internals (vs forged)
-less aggressive cams
-diff compression (?)
-diff gearing in tranny (?)
-plastic intake manifold (?)

 

i agree on most of what u said retro, but why plastic mani?
and i guess around 10psi only

 

That seems to be the current trend in cost savings... the new GTS has a plastic mani as does the new wrx. I guess it's lightweight, cheap, and holds low boost well enough. Personally I think . I don't think they'd dare put that in an Evo or STI.

You can see the plastic in this pic and the next...

 

The plastic manifold helps dissipate heat faster too.

 

i wonder how much pressure it can hold?
i hope someone(wink wink RRM/RPW) does like a pressure test to see how much stress it can handle before exploding

or maybe do a replacement one from something stronger