GCS..most all the ball manufactures have a drilling info sheet on their web sites. They also have some added info that will help you determine the type of ball reaction that you may be looking for. Some good ones off the top of my head are Brunswick, Ebonite, and LaneMasters. Also you can go to the reviews that have been written on your ball, and what the reviewers have found that works with the drillings that they applied. Read all of that, then get an idea what you think you would like and then go have a talk with your driller,..if possible, and he's not familiar with your game, have him watch you bowl a game or so,...by then he should come up withs what best for you if he's any good..je
