I would read that to be a GsR head flows better. If your cam has .4" of lift (how much is that in metric) you actually spent the majority of time between .1 and .3 of lift, and the average flow numbers at those numbers are slightly better (.8, very very damn close) for a GsR, that combined with the smaller combustion chamber of the GsR head should make it superior....however, the Type R's use the Pr3 style head????? Does anyone have flow numbers of the Type R head versus a GsR head? Say I could pick up a GsR head for a straigt trade of my B16 head, should I do that?