Start thread hijack.
Good question. I have heard rumors of the "bad batch" of gears 05's are infamous for being from Mexico but I dont believe it. I have also heard that some Toyota axle components are sourced from Dana. All 05 and up diffs I've looked at have similar markings complete with kanji. As far as I know the engines, trannies, and drivetrain components are all from Japan. The rest (body, bed, interior, wiring, etc) is sourced in North America and assembled at NUMMI here in Fremont, CA
The only way to get a 100% Japanese 4WD Toyota nowadays is to buy a new FJ, or the big $$ Land Cruiser...
Or a classic like Ed's.
End thread hijack.