There are over 100 differences to the JDM models. The ones that come to mind are. Transmission cooler added to ADM model, speedo changed to 280 km/h, different tail lights to have amber turn signal, roof aerial for radio, different cassette player, different rear bumper number plate surround.
Plenty of other differences, third brake lights, seat belts, sun visor, english decals instead of Japanese etc etc
Attached is a document from Nissan that has all the differences and the part numbers.
Nissan Skyline GTR R32 Australian Delivery - 10 page Nissan Document.pdf