Personally, I wouldn't hesitate on the 2004. GM designed the 8.1 for medium duty trucks in mind with a 200,000 mile durability standard. Chances are, the 8.1 in the burb might have towed on an infrequent basis. No where near the strain it would see in a Medium duty or 22,000 pound GVW motor home. I'd look at the condition/function of the trans and 4wd systems and if they work like they should, change the fluids and go. Yes, a 12 year old rig is going to need some stuff like an alternator, battery or a/c compressor along with going through the steering/suspension. For the price with little put in for PM, you have a rig that can do everything you want it too. Pull the trailer, haul people (you would need to find 3rd row seats for it) and eat up road miles like a champ. Keep the search going, but I bet you'll find the older you go the more miles the rig will have.
That truck has 176k miles. If it has a 200k mile durability standard or what not, doesn't that put it at the end of its lifespan?
I don't care about alternators, batteries and belts. Those are things that 5 year old cars need. I care about spending a ton of money on a truck that the trans could quit on, or the engine could have a catastrophic failure.





