As a point of reference……..
On a stock 596 head, I put a straight edge against the bottom of two intake bolts and scribed a line at that point on the port center divider.
That line is 1.135 from the bottom of the head.
The bottom of the intake ports are .400 from the bottom of the head, top of ports 1.530 from bottom of head.
If i scribe the line you mention, from deck surface to line is about 1.100", the floor of the port is about 0.675" from the deck surface, and the ceiling of the port to deck is about 2.700" (im assuming you meant 2.530" in your post).