Wow, looks like I have an interesting issue (Fortune cookie: May you live in interesting times). I may take a step back and consider a replacement high side line that has a more suitable port. The system is empty so now is the time if I want to make changes. Really appreciate the comments, I'm sure ...

Hello, I have a 1978 Pontiac Trans Am that originally had factory air. I've replaced all the system parts (Compressor, Condenser, Evaporator, Hoses/lines and Electrical). This will stay as a R12 system. The Pontiac Service Manual states that the high pressure line should not be connected to the syst...