well they have a dyno plot showing a b18c on a b18b that the torque is lower and then they have another dyno plot right next to it showing the flow rates of both heads and the b16 flows better. ill believe this author over other sources because he has been in it since he was a little boy and has had the chance to play with all diff types of setups and he has several setups that are pretty nice one of them being a 820 something whp b18c1 engine that is torboed and nitrous fed. i think that is pretty sick.