The ball could end with bottom weight, especially if there's no extra hole. This will cause the ball to have less backend, than if it ends with top weight.
You will need to place the balance hole past the equator of the ball(6 3/4" from the center of your grip) to increase top weight, giving the ball a stronger backend reaction. Drilling an angled hole may be preferred, in order to miss the track from flaring over the extra hole. =:^D