You mean the factory cut into the plug boss?
In the one pic where it’s visible, there hasn’t been any porting yet.
As for flow....... it doesn’t do anything to round that over.
Did you say the unported SM's flowed about 250 and I believe you posted numbers about x heads and J heads not be past the 230-240 mark?
Obviously I'm just seeing if I may get a bump in flow?..