Race Car Renovation
Actually it is best for the coil to be mounted straight up. It keeps all of the coils windings submerged in oil. Yes I know the factory did otherwise and most never had a problem. If you have a coil that was filled just less than it should be eventually the coil portion that is not covered by the oil, is then not cooled by the oil. I even had the coil on my house heat pump fail due to that, In that industries it seems to happen more then on our cars. It was mounted side ways like how the factory did on our manifolds.