Yep, that's a standard 16/40 amp regulator. The 16 amp charging system uses 1, and the 40 amp V6 uses 2 of em. Try unplugging all of the connections at it and see if that stops your arcing. The blocking diode inside could be bad and would drain back to ground all of the time. That regulator style though should peek out at 14.2 volts. Clean your grounds first as a poor ground could cause ALL of your problems.

The regulator was mounted next to the oil pumping system (plastic). Now removed, it's now mounted on the intake cover (plastic) and the ground connected thru the mounting bolt.
Don't hold your breath, I'll get to this soon....
THANKS, Benny