I have found a 2001 suburban 6.0 with 160,000 miles on it. Its clean and seems to run well. Outside of the obvious is there any known issues with the 2001 6.0 or can these beasts run into the 200,000 + range?

 

Sure it can. It all depends on lots of factors like regular fluid and filter changes, driver usage and many other factors. Cheap gasoline and cheap oil wont help things. You might want to run a CarFax on the vehicle. Well worth the money, or have a mechanic check it out or both. Use synthetic fluids and good gasoline and it can last a long time.