If you are running modern radial tires you should not follow factory alignment specifications for caster, SPC recommends 3° of caster to promote return to center steering. Stock strut rods on the 1st generation Mustangs are non-adjustable and often haveworn bushings that can cause unwanted movement of the lower rod assembly and poor handling. A must for early Mustangs, SPC's adjustable caster rod features low durometer OE-style bushings to protect the chassis mount from damage and has easy caster adjustment. It will provide the positive caster needed for improved tracking and modern geometry. If you want to adjust camber as well, look at SPC control arm kit # 94215.