FIT System Chassis Stiffening Kit

The Stifflers FIT System is a comprehensive chassis stiffening kit for 2005-2014 Ford Mustang GT and V6 models, including convertible configurations. By integrating the front and rear subframes and tying them into the rocker panels, the system creates a triangulated web that prevents the unwanted twisting and bending that occurs during everyday driving. This increased structural rigidity allows the suspension to function as designed, providing a noticeable improvement in handling, ride quality, and traction during launches. Built from durable mild steel tubing, the kit features sealed tube ends to prevent internal moisture buildup. The design is non-intrusive, requiring no floor cutting, interior disassembly, or line relocation. Please note that this kit will not work with side-exit exhaust systems. Factory convertible braces may be used with slight modifications. The FIT system also integrates with the lower torque box to provide additional reinforcement for control arm mounts, helping to transfer more power to the ground rather than wasting energy through chassis flex. By stiffening the platform, the kit helps eliminate interior rattles and may extend the vehicle's service life, while also providing an increase in side-impact safety.