Are the rails original? If they're the correct set of rails they should flush-up with the laminate and hit the ball dead nuts at 1 13/32. Valley's quality control was pretty tight. Maybe somebody fiddled with the table or the rails are not original and were drilled wrong? If you absolutely have to you can hog out the holes in the table to 3/8" and use a flatwasher under the head of the rail bolt but it sounds like someone made the rails and figured close was good enough. It's ok to have a little space under the rail by the way, wont hurt a thing. But the critical item is that it the balls hit the nose of the cushion (the pointy part) at 5/8 of the ball's diameter.