Reference Part Number:12633904,12574294,12558013Fitment: 2008 for , 2006 for , 2009-2011 for , 2007-2009 for Envoy, 2006-2011 for 1500, 2004-2011 for 2500, 2004-2011 for 3500, 1999-2012 for 1500, 2007 for 1500 Classic, 2001-2003, 2005-2006 for 1500 HD, 2007 for 1500 HD Classic, 2000-2004 for 2500, 2001-2012 for 2500 HDFitment: 2007 for 2500 HD Classic, 2001-2006 for 3500, 2007 for 3500 Classic, 2007-2011 for 3500 HD, 2000, 2002, 2005-2011 for , 2007-2011 for XL 1500, 2001-2006, 2008-2011 for XL 2500Fitment:2006-2007, 2009, 2011-2012 for 2003-2005, 2007, 2009-2011 for Escalade2007-2011 for 1998-1999, 2001-2002 for 2009-2011 for 1997-2003, 2005-2011 for 2006-2011 for Express 15002003-2006, 2008-2011 for Express 25002003-2011 for Express 35002007 for 2006 for 1999-2011 for 15002007 for 1500 Classic2001-2003 for 1500 HD2007 for 1500 HD Classic2000-2004 for 25002001-2011 for 2500 HD2007 for 2500 HD Classic2001-2006 for 35002007 for 3500 Classic2007-2011 for 3500 HD2006-2011 for 15002000-2003, 2005-2007, 2009, 2011 for 25002000-2004, 2006-2011 for 2006-2009 for Trailblazer2003, 2005, 2009 for H22009 for H31998, 2000-2002 for 2009 for G82005-2006 for GTOfor LS1 LS3 LS6 4.8 5.3 5.7 6.0L 6.2LColour:SilverMaterial:MetalPackage Contents:5 x Timing Cover GasketOnly the above package content, other products are not included.Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +\/- 1-3cm.