Ensuring proper operation of the water pump in your LB7/LLY Duramax is extreamly important ecspecially on modified engines. The factory Duramax water pump is known to slip under load and can serious problems and serious repair bills on modified high-horsepower applications. This updated design is a drop-in replacement for the factory water pump and uses precision TIG welds to secure both the impeller and pump gear to the shaft. If your 2001-2005 Duramax powered truck is running a tuner, a bigger turbo, or bigger injectors, or if it's just time for routine maintenance, get peace of mind with the Sinister Diesel Welded Duramax Water Pump.