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 late 1st generation Mustangs ('68-'73) are non-adjustable and often have worn bushings that can cause unwanted movement of the lower rod assembly and poor handling. A must for early Mustangs, SPC's adjustable caster rods features low durometer OE-style bushigns to protec the chassis mount from damage and has easy caster adjustment. These adjustable strut rods will provide the positive caster needed for improved tracking and modern geometry. If you want additional caster or want to adjust camber, check out SPC control arm kit # 94213. <br><br><a href=http://spclty.co/prop65 target=_blank><b>California Residents WARNING</b></a>