Here's a descriptive link for the labryinthe seal from red's headers. For some reason, the illustration referred to doesn't show up on my computer.
http://www.reds-headers.com/html/red...e_talk_24.html . At any rate, I don't think this is the problem. Try to avoid overfilling --- I have an early 38 221 with a labryinthe seal --- little or no leakage with 4 quart refills instead of 5.
Jack E/NJ