I have a 2002 & 2004 Chevy k3500. I only have about 70,000 miles on each. The 2002 had injectors replaced at 40,000 under warranty. GM extended the warranty on the injectors for the 2002 (110,000 miles/ 11 years(I think)) They're great trucks.
I bought a 2001 Duramax 10 dump new. It was the 1st Duramax in town. It had several problems. Axle seal leaks (drivers side ...twice) , gas gage, reprogram the transmission a few times. It went to the dealer probably 20 times. I traded it the day before it was 3 years old. It had about 35,000 miles on it. 1st year production of most vehicles: you get to be the test dummy.