I also have JDM ITR five lug for the front and I put one of my stock USDM B-series axles into the hub and it fit fine. There is no play at all and everything seems to work fine. The only thing that I am worried about is possibly the depth of the JDM ITR hub. I can get the nut onto the axle once it is thru the hub but this subject is and has been confusing, always hearing different views here and there. I will take pics tonight when I get home of the axle in the hub and then with the nut on to show you guys. I will post the pics tomorrow.
-Ryan