PPE 116111000 HIGH-FLOW EXHAUST MANIFOLDS WITH UP-PIPES LB7The PPE 116111000 High Flow Exhaust Manifolds with Up Pipes for your 2001 2004 GM 6. 6L Duramax LB7 increase exhaust flow by 20 percent and are 50 state emissions legal. Designed to outlast your truck the manifolds are made from high quality cast iron and the up pipes are made from stainless steel. Plus the aircraft grade Up Pipe bellows are high flow, internally sleeved, and have an increased inner diameter. FEATURES: CARB E. O. D 701 19 Significant