Banks PowerPack features a revolutionary new Ram - Air intake system that delivers greater airflow and air density for more power. A pair of stainless - steel, tuned - length TorqueTubes exhaust manifolds provide stunning torque output when you want it. Pass, merge and climb as you please your PowerPacked coach won't break a sweat. Achieve best gains of 70 hp and 92 lb - ft torque at the rear wheels, with better fuel economy - and never require high octane. Important Some vehicle configurations require an extension kit for proper fit. Note Banks Ram - Air intake system available for W - Series only. P - series chassis with wheelbases over 190 inch require extension kit. W - series chassis do not require extension kit. Includes Ram - Air Cold - Air Intake System, TorqueTube Exhaust Manifold System, Monster Exhaust System, Chrome Tailpipe, Heatshield, Banks Power Urocal, CARB Decal, Includes all necessary hardware. US Patent 6,634,171 B1