If you look under your hood right now, you will see that the end of the engine harness is connected to another harness which goes thru your firewall on the left side of the engine bay. In japan, since the drivers seat is on the opposite side, the wireharness actually goes thru the firewall on the right side of the engine bay. So its very hard to use the jdm harness because it wont reach.

Also, the fuel rail is backwards as well.