Machine description: Caterpillar 3126 6 Cylinder 7.2 L Diesel Engine, 2008 US EPA Label, Automatic Transmission, 8100 lb Front Axle, 17850 lb Rears, 25995.0 lb GVWR, 295/75R22.5, Spring Suspension, 176 in Wheelbase, EW1-1... more info about the 1998 GMC 6500.