I'm actually trying to work out this customs stuff myself. Got sent a couple of things by nengun, and customs have sent the appropriate forms to fill out, just impossible to figure out how to fill these forms out... asks for a 6 digit tariff number which you have to find yourself on the website but can't find any tariff listing for engine parts. exhaust - yes, steering -yes, diff and axels - yes, chassis - yes, blah blah blah, but no engine or engine parts.... Hate this...