yes Pop's is correct, you will need to trim the ball cups, there is a little circle on the under side of the ball cut ( aka ejector pin, from the mold) just cut the ball cup in the middle of the circle with a Brand new Exacto blade.
in addition, if you have not yet changed it, i would highly recomed picing up the light weight king pin set Part# sd-414ta.( once again more threads less change of stripping out )