I have no idea what the previous owner had in my car when I drained it, but the oil was not sour or overly dirty. I have a '67 400 with the factory cam that has been out of service for 10+ years, little wear on the factory cam. No sludge in the engines either, just badly worn cams on otherwise good engines. Old Yellow Bird is still running the flat cam until I decide to park it for a while to take care of all the issues.

I am starting a collection of dead cams. LOL.