RockAuto (or Dorman 610103 part number):
https://www.rockauto.com/en/catalog/dodge,1973,challenger,5.6l+340cid+v8,1078680,wheel,lug+stud,7680
When installing the studs don't be tempted to use the threads and a wheel nut to install them! I use a vise (Harbor Freight) and a deep socket. It takes...