so in Japan they are just running at lower boost levels?

No............

well I guess I was vague and I apologize. I understand the easiest way to make up the HP difference would be to increase boost that is obvious. But I was just generally inquiring about what caused the difference in hp, if it was just lower boost being used or the internals were causing the difference.
(I know some people may say well duh, different internals will give different results, but thats not always the case, I was just curious)
Thank you for the help pwpanas :)

It seems you pretty much already know the answer, as you posted above: "...the ECU...replace the turbo's...increase injector size..." :dunno:

The only thing you missed is the intake side cam (larger duration in the us-spec). Other than that, the internals are identical.