Only problem is that I have 8 balls to change the thumb on.
Try it out for a little while. If you like the fit, best thing to do is to take them all into your driller at the same time and get them done. I know, it's expensive. But, if your driller has them all there and does them at the same time, it will be easier for him to get them all the same. In April, I had 4 balls redrilled to a different span, different pitches, and no finger grips. Why? So he could exactly match everything up at the same time. I got a
Cell a few weeks ago. After about a week, I had to get my thumb sanded cause they were all tight. I brought all 5 in at the same time. My driller thanked me. He said that it is easier to match equipment up when you are doing them at the same time rather than one at a time.
Getting 8 done at once will take some time. Make sure that you have a few days until you have to bowl again. Also, let your driller know what you are planning to do. That way, he can schedule it with you.