This version of the RS Cusco differential fits the IS350, IS200t, RC350 (model year 2006-2013), and GS350 (2006-2012) RWD models (please refer to a complete fitment table below). Our 700+hp Supercharged ISF shop car was equipped from the factory with the Torsen differential. Although better than the open differential in the 2009-09 ISF’s, it still leaves a lot to be desired. We have found that it allows significant amount of wheel slip, particularly in low traction situation or bumps, so we set about tuning our Cusco RS differential to address these issues. We achieved all our goails including: