W2 head porting observations help needed!

Looking at the pics more closely....... it appears as though the middle of the floor of the old head has been lowered to create that rounded shape...... or its cast that way.
If someone did that, I’d tread lightly trying to fix it.
Seems like an easy way to make a hole.

If it’s cast that way, then you obviously have more material to work with.

Like I said...... limited experience with w2’s, so I can’t speak to what kinds of variations there might be to the ports of the different generations of casting.

You could try filling it with some clay and seeing what happens to the flow.