I can custom make you a bracket to convert your JDM front bumper to be compatible with your United States Licence Plates. Braket is made of sturdy aluminum. I know that this will fit any S14 JDM Bumper such as a Silvia Zenki as well as the Silvia Kouki and will also fit the Navan bumper as well. It should fit an S13 JDM bumper as well but it has not been tested on an S13 yet.
Complete Bracket as pictured minus screws: $25.00 plus shipping.