Its going to be impossible for anyone to give you an answer. The revolver is a real good ball. It does need some oil, or a bowler with a lot of speed.
Ball selection depends on the lane conditions, and bowlers specifications. I feel, you should visit your local pro shop and discuss this with him or her. They will need to see you son bowl and if the shop is in the center that he bowls in, they will know the lane conditions and be in a better position to help you make a ball selection.