"Port" or Starbord

--------------------------------------------------------------------------------

I have a "Q" about a ported exhaust mani.

1) What exactly on the mani is ported (if I were to buy a Buschur), I understand gasket matching the turbine housing flange. Is there any advantage of porting the exhaust primary flange? Doesn't the head need to be ported for this to net you a gain? (I'm not going to port my head, nor would I ever attempt to do such)

2) Is there any porting inside the bore of the primaries? Just smoothing? Cast leaves a rough / matte finish.

3) What is the alloy of the casting? I know this is a longshot, I don't want to tap threads into the casting for fear of splitting it or ability to cut a proper amount of threads to get a good seal. My buddy Nater is a "wiz" w/ the Heliarc, and Venus rod. I was thinking of letting him weld me a bung.

I have all the tools at my disposal to do this, virtually all the die grinders, abrasives, CNC mills and lathes. I just need to know how involved it is.

Or,

Would I be better off fixing my "Cracked Megan Mani" , gasket matching the turbine flange. and welding on a gussett for support?
I honestly care nothing for the Megan mani, and have been told by my tuner to ditch it and go w/ the ported stocker.
Being in the pipe industry, I do like the looks of the thing, and polished stainless heat rainbowed is awesome.--------------------But------------------------
Which one has superior flow. Keep in mind the FP green hanging on the end of the gosh darn.

 

The four runners are ported (where they connect to each port on the cylinder head) and also the collector is ported (not sure if Buschur does this part but normally it is done). For optimum performance the exhaust manifold, turbine housing and O2 housing should be ported at the same time.

The OEM manifold, turbine housing and o2 housing are all cast iron (Straight FE, not an alloy).

 

The mani has to have Ni in it or internal/external corrosion would kill it.

Also, how would porting the primary flange benefit you without porting the head?

I have all the other parts ported already.