DOD water pump on non DOD ls
"The same is true for the C/K truck pumps. The 1999–2005 trucks use a specific water pump, but in 2007 the design changed to DoD. Not all 2007 C/K engines use this pump. The offset remains the same as with early pumps, but you do not want to swap a DoD pump onto a non-DoD engine. The LS1/LS3 pumps are interchangeable; the LS3 pump uses a lighter pulley, with about 4 pounds of weight savings."
This is a good comparison of three different OE style oil pumps: http://www.norotors.com/index.php?topic=10219.0



