My old Merc (55) has 2 Carter 4 bbls on it and started blowing black smoke out the tail pipes. I kept the car original 6volt when I restored it  and added the dual carb setup later. The problem is the coil needs replacing and the websurfing I've done I can find a hot 6volt coil, anyone out there have a clue if they are available? Tnx Terry

Terry