I Don't know....however....
A popular upgrade to the mk2 Golf 1.8 8v is a 2.0 conversion, using a 2.0 bottom end but the original (1.8) head, primarily, for a torque increase. Whether this is because it breathes more through better port design or whether the cam gives this advantage, I don't know.
Seems related though, maybe it will add to the discussion.