Thanks again for the input. The coil is mounted exactly where and how
it has been mounted for the last ten years, and nothing has changed
with the engine. So I think, since the problem has developed in the
last two years, we can eliminate mounting or external heat induction.
I will check with a local speed shop and see what I can find out about
a high performance coil, at this point I will try anything! I will
also try cutting open an old coil if I still have one of the burned out
ones, if not I will check the next one that burns. Hopefully, since I
just had to change it, it will not be for a while!! LOL.

Thanks
Ronnie