Different brands of idler arms often position the drag link in different planes of operation in relation to the pitman arm. And the exact position of the idler arm mount on the 'K' can vary from car to car. All of that changes the arc. It is nearly impossible for most of us to know where the ideal position of all of it should be. And how can we be sure that the pitman arm is in it's correct plane. To say that bending an idler arm that may have the wrong angle to begin with is a bad fix, may not be true. I am not sure that bending the idler's mount on the 'K' to correct an improper angle on the idler arm itself is a better solution. And some folks may not be anxious to burn the paint off their 'K' member. But to each his own.