the latest new or re-manufactured compressors can use either or r12 or r134, the important thing is to evacuate the system and make sure you use the correct oil for the refrigerant used. I normally use PAO 68 which is compatible with both refrigerants.You can also use PAG ISO 46 for R134A applications. And regarding the connector you can splice in the one from your old compressor and it will work. Make sure to evacuate the system properly. Then replace the drier. Add the oil per the FSM if they are new compressor and drier. Good luck.