1973 Dart AC compatibility with 1970

I’ve got a line on a complete ac unit locally from an acquaintances 1973 Dart parts car. I have seen in one place they are the same as 1970 until sometime in 1973. How much of it would fit my 1970? He also has a new in box Chrysler style compressor I might can get. I know the kits use a Sandon. What are the pros and cons of a Chrysler style compressor?