I think putting it up with a 325 cfm carb and a header would be a typical 20r. The reason I'm interested in this is that my 20r has clearly different and more eager driving characteristics than my 22r. That head is really doing something despite the smaller 2.2 displacement, even bone stock.
I know it's probably not possible to account for the better flow of the head but it would be fun to see what the smaller cubes and square bore/stroke relationship do to the numbers.