2005-20 Ford F250/F350 4WD. 2008-19 Ford F450/F550 4WD. Fabtech's legendary Radius Arms are the perfect upgrade to the Ford Super Duty front suspension for lifted applications. The heavy duty tubular construction adds strength with a race component style to the vehicle for aggressive offroad use. These Super Duty Radius Arms directly replace the factory arms for use with lifted 4in to 8in suspensions. The arms have an additional 1 degree of caster built into the arms and with the easy adjustment alignment cams gives a total of 2 degrees more caster than stock. A big benefit for taller 6in and 8in lifted vehicles to improve highway tracking. The upper and lower tubes of the arms are constructed with 1.75in OD x .120in wall DOM tubing and are fully welded closed to prevent corrosion. Spanning between the tubes is a dimple die side plate that adds rigidity to the arm for strength with minimal weight gain. Radius Arms are offset and positioned inboard compared to the stock arms to allow full steering lock with a 13.50 wide tire on a 5in backspace wheel. The Fabtech Super Duty Radius Arms are an open design so that powdercoat can cover the entire arm. This design is superior in coating coverage compared to boxed arms that are stitch welded and have gaps that allow moisture to get and cause rust. Fabtech's Radius Arms have been proven for over 15 years in consumer commercial and military applications. There are no better Radius Arms for your Super Duty. Features: Constructed with 1.75in OD x .120in wall DOM tubing. Directly replace factory arms on lifted vehicles. Additional caster to improve tracking.