2WD:

FROM 2007 TO EARLY 2016, 2WD GM TRUCKS ALWAYS CAME WITH CAST STEEL CONTROL ARMS

FROM MID 2016 TO 2018, 2WD GM TRUCKS ALWAYS CAME WITH STAMPED STEEL CONTROL ARMS

THE ONLY YEAR THEY OFFERED BOTH IS 2016. YOU MUST VERIFY AS TO WHETHER THE TRUCK CAME WITH CAST STEEL OR STAMPED STEEL CONTROL ARMS

4WD:

FROM 2007-2013, 4WD GM TRUCKS ALWAYS CAME WITH CAST STEEL CONTROL ARMS

FROM 2014 TO EARLY 2016, 4WD GM TRUCKS CAME WITH EITHER CAST STEEL OR ALUMINUM CONTROL ARMS. YOU MUST VERIFY WHICH ARMS THE VEHICLE CAME WITH

FROM MID 2016 TO 2018, 4WD GM TRUCKS CAME WITH EITHER STAMPED STEEL OR ALUMINUM ARMS, YOU MUST VERIFY WHICH ARMS THE VEHICLE CAME WITH