LBP Brakes

I have a 1967 Dart GT with factory front disc brakes and rear drum brakes with the small bolt pattern lugs. I want to convert to the large bolt pattern lug setup. I have found the rear axles assuming the only other thing I need on that end would be the 5 lug drums. My question is can I just buy new front disc brake rotors with the large bolt pattern lugs to replace the rotors I currently have or do I have to replace everything? Thanks in advance.