New castle nut for all power steering control valve ball stud found on 1967-70 Mercury Cougar and Ford Mustang. 3/4 inch hex nut, with 1/2-20 threads. Connects the Pitman arm to the ball stud on the P/S control valve. Don't forget the cotter pin.
Verify your shop manual for correct year torque specifications. We found one source of 28-35 FT LBS. for the Pitman Arm nut to control valve.
Ford numbers for attaching nut: 1967-68 351059-S, 1969-70 385002-S.