Revolution Gear GM 14-Bolt 11.5" 4.10-4.56 Ratio Ring & Pinion Set. Fits: 2001 - 2004 Chevy/GMC 6.6L LB7 Duramax; 2004.5 - 2005 Chevy/GMC 6.6L LLY Duramax; 2006 - 2007 Chevy/GMC 6.6L LLY & LBZ Duramax; 2007.5 - 2010 Chevy/GMC 6.6L LMM Duramax; 2010 - 2018 Ram 6.7L Cummins; 2011 - 2016 Chevy/GMC 6.6L LML Duramax.