Never ever should you need to bend the idler arm. This will change the arc of the idler arm causing toe change as the idler arm pivots. It is possible that the idler arm pivot bolt location is off from the factory. If the centerline is not level to the chassis this may be the issue. Is the center link higher on the right side? If the centerline is level, leave the idler arm pivot alone. Either raise the motor by shimming or put a small dent in the header. It will not affect performance at all. If the center link is unlevel heat the K frame bracket and bend it until the center link is level. It bends very easily with a little heat.
Doug