I have a 1983 K5. An aluminum line with the port for charging the system is leaking and needs to be replaced. However, even though this line looks factory it does not show up on any AC system schematic I can find. I will enclose a picture and would appreciate any help in identifying this part and part number. As you can see it is attached to the wheel well and has the charging port. Thank you.

 

I recently learned that there are businesses that can make custom AC lines. If you cannot the proper part, perhaps that is option for you.

Good Luck!