Open the drivers door and look at the door jam and you will see a sticker somewhere on it and it will have the factory tire size written on it.
The 2010 GMC Sierra-1500 has a V6 engine.
The 2011 GMC Sierra-1500 has a V6 engine.
The 2009 GMC Sierra-1500 has a V6 engine.
The 2003 GMC Sierra-1500 has a V6 engine.
The 2013 GMC Sierra-1500 has a V6 engine.
The 2004 GMC Sierra-1500 has a V6 engine.
The 2002 GMC Sierra-1500 has a V6 engine.
The 2007 GMC Sierra-1500 has a V8 engine.
The 2008 GMC Sierra-1500 has a V6 engine.
The 2005 GMC Sierra-1500 has a V6 engine.
The 2012 GMC Sierra-1500 has a V6 engine.
The 2001 GMC Sierra-1500 has a V6 engine.