Tail Housing for 2001-2006 Chevy GMC 6.6l Duramax W/ ZF6 Transmission Reinforced greatly in the rear where breakage frequently occurs Heavy duty die cast aluminum Precision CNC machined Fits: 2001-2006 Chevy & GMC 2500 & 3500 applications with the 6.6l LB7/LLY/LBZ Duramax or 8.1L with the ZF6 Manual Transmission Installation instructions: 1.