Hello I am looking at a 2005 GMC 2500HD with a 6.6 it has 114000 miles. Are these good engines and about how long should one last with proper maintenance. It is a one owner vehicle. Have owned a 97 Sierra 1500 for 9 years and need something bigger to pull a 5000 lb camper. Most of my friends have F 250s but I want to stay loyal to the GM brand.