This is the steering linkage support system: idler arm (right) and Pitman arm (left). This is a Pitman arm for power steering, solid and without the ball/socket attachment found on manual steering cars. We call these parts a support system because the idler and Pitman arms support the steering system. For '65-'66, the idler arm is typically a dog-leg affair that slides onto the body pivot (mid-photo). Mustangs Plus sent us the body pivot just in case we didn't have one or had a one-piece integral idler arm to replace.