The base does not need to be mounted dead center on the crank - I don't know why people think it does. You can mount it right out on the flat surface of the flywheel, it doesn't matter. The dial indicator will be in the hole and all that matters is that IT is roughly level with the flat surface of the bell and, for lack of a better term, square to the edge of the hole. And it also has to point in the direction of the base.