Compatible with GM Duramax - LBZ - New Cylinder Heads Complete With Valve Train (2) This product listing contains the following part(s) Compatible with GM Duramax LBZ applications: (2) Brand New Cylinder Heads with All New Valve Train Components All NewValves, Springs, Seats, Seals, Retainers, and Keepers All of our heads are brand new with complete valve train including black nitride coated valves. Limited 1-Year Warranty Special Notes about the Product(s): Please verify your engine model before purchasing. The 2006 Engine can be either a LLY or LBZ. This cylinder head WILL NOT work for LLY engine applications. This product listing is Compatible with GM Duramax LBZ - VIN Code '2' GM Duramax LBZ - VIN Code 'D LBZ head casting number 476-1.