The ones on the car when I got it were part #3574116-7 (potmetal) and have the threaded studs.I bought a pair of NOS ones,#3573788-9 (potmetal) and they have the smooth,molded in studs that I assume would use the pal nut like you showed.These are also listed in the parts book as up to 12/01/71 and I also bought a pair of NOS #3574148-9 that the book shows after 12/01/71 (I have not received these yet,but will post what material they are made of) My car was late 72 production (April 72) so according to the book,my car should be this last number...but