Exactly where abouts is the screwed thread?Front,back?how many holes from the left hand side ie the crank pulley.is it a blind hole or one where you can see it coming through the block?Unless its a hole near the flywheel/bellhousing I dont think there is a need to start talking about taking anything major out.I would go back to where you had it fitted originally and start pointing the finger.Its not worth getting rid though mate.When you calm down you will want to keep it.