Personally, I would keep the one with fewer hard miles. In your case, I think I'd keep the 100 series since it's built mildly and you've maintained it very well. If it's a true expedition truck you want, then keep the 80, but I think the hundy will do most any trail short of Rubicon that you'll take it on. I've often looked at my truck and thought about it what it's worth. So sell it, take that money and beef up the other vehicle into something off highway worthy and be happy...