I would expect you to have already known this from years ago. It's a fact that the B16/B18C5 ports are larger than the B18c1. This has been around since the late 90's. I have no idea who initially did the test but yes it was proven that the B16A head Flows 10% more air (cfm?) over the B18c1. And I do remember seeing some kind of proof back in the day. Look it up I'm sure you can pull the data sheets off the honda-tech archives. I don't really care enough to do the homework.