Update! This was a little delayed, as the o2 sensor was not super psyched about leaving the stock o2 housing, so I ended up replacing it
First off, BIG thanks to Chris Hughes (s2kracka) for overall help as well as some guidance with the porting I wanted to do. We ended up taking a bout 1-3mm (maybe 4mm on one side? I can't remember!) of of various portions of the twin-scroll turbine inlet. Nothing major, but in the end I would say it is definitely worth doing. Sorry I did not get a before pic, but here's after. We basically just gasket-matched it, just like the exhaust manifold is:
[img]http://www.scheides.com/albums/evo8/IMG_2874.sized.jpg[img]
We also found a little lip inside the o2 housing that we decided to mow down just a little bit. Again, nothing major, just trying to smooth out exhaust gas flow:
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