I also have a yellow sun storm.
Drilled righthanded. Thumb and fingers plugged once each. Thumb in same spot Just went from a slug to no slug. Fingers moved up about 1 inch.
Small pin distance. Extra hole about 5 inches from cg on midline.
There is a 1 inch by 1/2 inch gauge in ball, not very deep.
I can send pics of ball and gauge if wanted.
$ 30 shipped to your door.
Matt