The pocket castings on a GC have a throat opening of 4 5/16"s and its at that point on both side of the pocket casting that the miter angles swing out wider in oder to make the mouth bigger than the throat. If you start with the mouth of the pocket being 5" and open the throat of the pocket, all you're going to end up doing is creating a step from the end of the facing in the throat being wider than the pocket casting, which is clearly visible in the picture I posted. No camera angle can change that view, clearly showing the throat of the pocket being wider than the pocket casting as well as the pocket liner itself too. If you tighten the pockets, to say around 4 1/8" - 4" then you have to open the throat of the pocket up, so the miter angles defect the balls deeper in the throat making it possible to pocket balls, if you don't open the throat up with 4" pockets you won't be pocketing shit, and will even have a hard time reaching in the drop pocket to get the balls out, because you won't have any room for your hand to hold and balls and pull them out.