I am moving the toilet in a down stairs bathroom to the other side of the room (concrete already cut and dirt dug down to 10 inches all the way across). The new drain hole will be exactly 5 ft in a straight line from the current drain hole. The bottom of the current connection is 9 inches below the concrete. What kind of drop (angle) should I have from the new hole to the original connection, or is it even that critical? Thanks