Engines and modifications Silverado 2500 HD IV (T1XX) Double Cab Long Bed

6.6 V8 (401 Hp) Automatic

6.6 V8 (401 Hp) 4WD Automatic

6.6 Duramax V8 (445 Hp) Automatic

6.6 Duramax V8 (445 Hp) 4WD Automatic