BMW Repair: 134a conversion, york compressor, walmart

Question
looking to convert my 1979 320i ac to 134a (it stopped cooling going cross country last fall) other than replacing the receiver and flushing do I need to replace the york compressor or hoses.  I can"t seem to get a straight answer from anyone.
 
Thanks in advance....Jim

Answer
I know they say that you have to replace this and that when converting R12 to R134.They say anyways.I personally evacuate the system and then use the retrofit kits that you can get at Walmart.I have not changed any dryer or components like that in the conversions and I can get the temperature down to 37 degrees F