2004-2007 GM HD LLY/LBZ Duramax Manifolds and Up-Pipes Y-Pipe (116111600)Description PPEs Manifolds and Up Pipes are designed to maximize power and flow characteristics. The Up Pipe bellows are internally sleeved, made from aircraft grade 304 stainless steel and designed with an increased inner diameter for higher flow. The entire Manifold and Up Pipe exhaust system is designed to lower exhaust gas temperatures (EGTs) and accelerate turbo spool up while increasing power, fuel economy and maintaining reliability. Kit comes