I am talking about useing the perpormance reeds . The problem with the nc50 reed cage is that its openings are half the size of the power reeds . NC50 reed cages are super restrictice when you are running a 19mm or 21 mm phbg . Just trust me when I say you are MUCH better off takeing a tiny amount of material from both sides of the case s intake opening to fit the much larger reed block of the nu50 or pa50 . I will have to post a pic of the two side by side later when I get home . You will understand then .