Sounds like SOP for an old 216. My 49 216 does similar during the winter months. Your probably getting that milky buildup on the bottom of the oil filler cap too. Like HRL says, condensation is the most likely cause and you'll get it more so in cold weather.
To try to combat condensation I went to a 180 thermostat, installed a PCV valve in the draft pipe, went to a vented oil filler cap and plugged up the vents in the valve cover and I still got condensation build up in the cold winter months.
You'll want to keep your oil changed at no more than 3k mile intervals.
re. oil drips. If you see a 216 that isn't dripping oil, you better check it as it's out of oil LOL
Dave
