I had an 8.1L in a 2001 dually; it was a great engine, smooth, quiet, powerful. I wouldn't worry about the age or the miles. My families current rides are: 2005 Chevy 3500 with 248,000 miles, 2002 Grand Cherokee with 210,000 miles, 2010 Buick with 211,000 miles, 2009 2500 Suburban with 105,000...