Fabtech 17-20 Ford Raptor 4in SystemFabtech's new 4? System for the Ford Raptor provides increased suspension height to allow use of 37? tall tires while retaining the factory SVT control arms and Fox Shox. The system features heavy duty ductile iron steering knuckles designed to handle 37? tall tires with the vehicle? s ESC (electronic stability control) and Traction Control. Typically 37? tires will cause steering and brake issues on the factory Ford steering knuckles. Fabtech