Weird engine trouble

[tortuga]

So we took the wife out for a ride. Stopped for an hour, and just as we were leaving the engine started ticking/tapping. Sounded like an exhaust leak, so we drove home easy…

Background, 427 stroker, Big hydro cam, 850 dp, trickflow r manifold. Just recently discovered a bad ground at the battery, and fixed it. Car was cutting out periodically, lug was actually cracked in half…Msd 6al box. Have a spare, swapped it out and no change.

Got home and started troubleshooting, discovered that the tick/tap stopped when plug wire 7 was pulled off the distributor. Tried switching pugs and wires no change. There does seem to be a periodic arc at the plug. But insulating the heck out of it by wrapping it in a sliced hose didnt help.

Reading the internet i am worried i have a bad rod bearing? Seems strange that it would cause arcing at the plug?

I drained the oil, and see nothing in it…havent cut open the filter.

Any ideas?
Thanks
Steve H
Spf 1764