Hey John,
The fact that they call it a street port tells me they have the same thing in mind as the big block heads. This head is meant for good port velocity for street use, and flows pretty well for a 2.02" valve. From the big block heads I've been working on, I can say that the port is very well balanced with the valve size on the 270s, and predictably small for the street port 240. The 240 still makes good power though. I'm thinking they'll do well with a competition port version of a small block head too.