EFILive Transmission Tuning Upgrade | 01-10 Duramax | by Kory Willis of Power Performance. 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.