HighFlow Exhaust Manifolds With UpPipes

High-Flow Exhaust Manifolds with Up-Pipes for your 01-04 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 Significant reduction in exhaust back pressure Free flowing Stainless Steel Inner Liner. Stainless Steel 11-gauge. 120 in. wall diameter Up-Pipes Built in bosses, pre-drilled and tapped 0.12 in. NPT for EGT gauge 2001-2015 GM Duramax 6.6L, Race Manifolds & Up-pipes