School me on W2 heads.

My W5's ported by Brett Miller 2.00/1.60 Ti valves polished tool steel valve springs, max hand ported until epoxy was needed. So we went no further. The intake is a M1-W5 large port.
Do take note of the flow rates between the different bore sizes and keep that in mind when you read them on other sites and when your building your own engine. Sorry for the blurry flow rate photo.