The correct Roadmaster Front Anti-Sway Bar Kit for your 2021 Thor Magnitude Motorhome built on the Ford F550 Super C, is # RM35VR. I have verified with the manufacturer that this is compatible with the F550 chassis with a 4x4 front axle.
This Roadmaster anti-sway bar is made of 4140 chromoly which is considerably harder and stronger than the standard 1020 steel commonly used in OEM installed components. In addition, this has a larger diameter that also increases its torsional roll stiffness... view full answer...