Lou,
I have the same setup and experienced the same situation too many times.
I got tired of replacing the MSD cap, which burns out the center contact, ripped all MSD equipment out, and now run a Pertronics setup with NO issues.
I tried the MSD tech bulletin fixes, like more and better grounds and drilling holes in the cap to no avail. Been there and done that and have a drywall bucket of wires and MSD stuff for the FE if anyone wants it.
David A.