Here are my two, both 98's. The ext-cab Z71 I bought new and it now has 120,000 miles on it and the K3500 I bought in November of 2007 with 94,600 miles on it now has 104,000 miles on it.
The Z71 has the 5.7L/4L60E combo and the K3500 has the 7.4L/4l80E combo.
Wayne