The Duramaxtuner Team explains the difference between the 2006 LLY and 2006 LBZ engines. Mechanically, the LBZ is nearly identical to the 2006 model year LLY. 2006-2007 GM LBZ Duramax Diesel Specs & Insight. Right out of the box, the LBZ produced 360hp and 650 lb-ft of torque. In 2006, production at Moraine was reportedly limited to approximately 200,000 engines per year.