Here is what I can share. I have a 98 R. Dyno'd it with just an AEM and it made 162.1/112.3
I since added a JDM 4-1/Carsound setup and a 00/01 ITR Inatke cam. Redyno'd (I was using my STOCK ECU) and made 178.1/125.3 So it seems there is about 16 hp to be had between a JDM header and an intake cam. Deducing from the header test that a JDM header is worth 5-7 hp that would leave me to guess about 8-9 hp is to be had from the 00/01 ITR inatke cam.
More than I woudl think and figure other factors and we mmight say 6-7 whp from the cam. Not bad for drop in. Especially since it cost me $90 (Cost of new cam minus sale of 98 cam)