Im looking at some low mileage dumps. One is a 08 350 6.4 diesel and the other is a 05 550 6.0, both 4x4 automatics. The 6.0 is about 6k cheaper and has only 19k miles. Which truck would you guys go with? I had a 07 3500 gmc and was hauling gravel and dirt just as much as I was hauling mulch. Which motor would be more reliable?