20,000 lbs combined towing weight. Horsepower and torque measured at rear wheels. Systems do not fit 2005 (3-valve) vehicles designated by a V in the 8th position of the VIN number. Stinger Bundle, Power System for use with 1999-2004 Ford 6.8L EC/CC Extended Cab and Crew Cab, S/D Super Duty Key Features Optimizes airflow, air density, continuous power and MPG Honors the host vehicle and improves longevity Rear-wheel gains up to +35 hp and +42 lb-ft Total Power System for Towing and Work 5 percent more MPG CHROME tip CARB E.O. Not Required