This seems like a very GRM rig. 1998 C2500HD Cheyenne that I bought 3 years ago as a tow rig at 162k miles. I've been using it to haul an open car trailer everywhere between Nebraska, New York, and Tennessee. About 15k of my 16k miles of ownership has been towing. It gets 11.5mpg whether you are doing 70mph or 80mph, and about 16 unloaded. It has earned it's nickname of The Cuck Truck and was the official sponsor of my 2018 ESP national championship.
350 Vortec, 4L80E, 3.73 gear, 8 lug hubs, 178k miles
New brake and fuel hard and soft lines
New front pads/calipers and rear drum hardware installed, with new Hawk rotors included with sale
Upgraded Bosch MPFI spider injector assembly
New fuel pump
Intake manifold gasket done by previous owner
Bilstein dampers
New E load tires last towing season
New front control arm bushings (except left front upper IRRC, it fought me) and sway bar links. New leaf bushings included but not installed
Hella headlights
New stock muffler
Trans drain/fill every year, filter change every other year
Curt Triflex brake controller, adjustable height 6k ball mount, and Weather Gaurd toolbox included in sale
It does have a hole in the driver floor that is (mostly) covered by a steel plate. It also needs the driver side door hinge replaced (parts included with sale) and because of that has a broken interior driver door arm rest. The air conditioning works though, and works as well as any GMT400.
Located in Columbus Ohio. Price is $2500 firm.