Est distributor hei ignition coil arching from the metal surrounding

[CitrusMcfly]

First time posting, be kind. I've tried searching for this and I can't find anything. Situation is I have a Crusader CH350 454 block with an EST Delco distributor in which I replaced the gm ignition module for a Sierra EST module Sierra 18-5101-1. After which I replaced the spark plug wires as well as spark plugs AC Delco MR43T's, I kept hearing a spark knock after feeling around everywhere I couldn't really find it but finally as it got worse touching the metal portion where the pen is pointing, I finally started receiving shocks and at this moment is capable of arcing about an eighth of an inch to nearest ground. My question is what would be causing this situation, if it is a bad coil, then how did this happen and will it happen again. I'm currently on the water so I can't just go out and buy one. Also what's the risk of simply grounding it to the engine or if I isolated it from ground?