From this man's description, his drain cock was completely missing and was just barely dripping! My guess is, someone in the past did not follow your suggestion of anti-freeze and distilled water and now may have a seriously plugged up water jacket. I unknowingly had this same problem on my first 216. When my original brass t-stat stuck closed one day and overheated, my water jacket cracked right at the top of where the crud in the water jacket leveled off. Coincidence, maybe.
