1974 Dart Sport “Desert Rat”

You would be correct! Detroit Muscle is what I used to restore this box. I’ve had really good luck in the past using the old lines and a converter oil with new neoprene o rings through out.
Those were all factory lines and the old style compressor.
I had a great shop back in Illinois that would charge the old systems for me and they really worked well.
My 1970 FM3 Charger has had R134 in it since 1998 with no ill effects as yet, I sharpe it every other summer but it does work.
I did an old 62 Dart 440 wagon the same and the current owner says it’s still blowing cold.

This being a new style compressor I think I will follow what you are saying and replace the rubber hoses on this one.

Thanks again for the suggestions!