A/C oil

Go to MyMopar and download the 72 Plymouth chassis manual, go to page 24-40 and read, especially on page 24-46. Earlier manuals may have that as well

67 Manual is about 24-36, that is the 67 Dart/ Coronet manual

If I ever get the 74 Scamp "runnable" I'll be into this as well. I did a very quick pressure check just shot som R22 in there "for pressure". In less than an hour on a hot day, the pressure went from about 130 to ?80PSI or so so "it leaks." I've no idea anymore, where my leak detector or halide torch has gotten off to. I may have to invest in another. No idea where the leak is ---yet