The only difference between JDM housings and ours are the protruding points in the front, USDM has them JDM does not. In the same topic it was discussed that the factory lenses are optically clear just like TRS.com sells but because our headlights have ridges in the glass you will not get a clean cut off. They also detail how dirt on the lense could play a bigger role in output than most would consider.
I couldn't find the acrticle you wanted but if u want to work with already in there here's some good reads:
