Difference between JDM & USDM enginees?

Ive bought a Japanesse engine and im wonder if theres any different with the EGR sistem n the inside of the engine?
I took alll the stuff from the usdm engine and put them back to the jdm engine so i just want to know if this iis going toi work for the emissions since the jdm engine is not drilled for the emissions? is it true???
well the jdm engine has the holes for the emissions and the bolts but iduuno moresabout the indside... IVE BEEN TOLD THIS, IS THIS TRUE? SEEMS TO BE RIGHT, RIGHT??? WELL IF YOU REALLY KNOW ABOUT THESE JDM ENGINES PLZ CA
By the way installing USDM emmisions equipment on a JDM engine won't work. The JDM head isn't drilled for the EGR system so bolting it on will only pass visual inspection, not the tests.
So the JDM head is not tapped/drilled for it, also the intake manifold is not drilled for it either. There is a hole in the #6 runner and a plate on the back of the engine for the EGR system, the mounting points are there, but theres no holes on a JDM head.

I thought i already explained this to you already a few times, maybe this will help.
http://www.supraforums.com/forum/showthread.php?threadid=135873&highlight=JDM+head+EGR
http://www.supraforums.com/forum/showthread.php?threadid=139762&highlight=JDM+head+EGR