Hello,

I had the same problem last year.  I went the HeliCoil route and used a
soft aluminum gasket.  I developed a leak after a few weeks, but I found
the drain plug quite loose.  Tightening it fixed the problem.

I matched the thread to the original drain plug, and it cost about $60 for
the fix.  In looking for the correct HeliCoil, I came across a lot of much
cheaper kits for spark plugs.  These are the same diameter, but a different
thread pitch than the drain plug.  And, the kits are about $25.

Has anyone used one of these spark plug kits, and made a new drain plug
from an old spark plug?

Thanks,
Mike         '84 GL