it there another mopar I can get the rotors and the rest of the stuff I need to change to disc brakes and the bigger bolt pattern ??? or is my only choise after market ???

thanks for your time  

73-75 dart, valiant, dusters, scamp [if a-body]
Get the upper control arms off of the above along with the rest=rotors,spindles,brakets, backing plates, calipers, ect