another lug nut question

Just got a new set of American racing 624769 wheels for a 71 duster sbp drum brakes, are the lugnuts supposed to be the acorn style or have a shoulder on them? The tire man sold me an acorn style nut seemed to work on 3 of 4 one front wheel for whatever reason does not have any thread sticking through the wheel and the others not much! Also the other front wheel weight is hitting the a arm. it will clear if I take the weight off but it will be close.