1699 2001-2006 Chevy GMC Kodiak Topkick 7.2L 7.8L 8.1L water pumpIf you have the 2001 2006 GMC Chevy Big Blocks that haul you might be finding it runs a little hotter under a load. We designed an impeller with an increased vane count and a reduced impeller vane clearance to take care of the problem. It achieves greater flow rates, higher head pressure and a more efficient flow. The impeller color is due to Type II Class II military grade surface coating which protects against corrosive fluids. FlowKooler introduced