Increase mileage on 1500 Van

I have a 98 1500 Van with the Vortec V8, 160,000 miles. I am planning a trip this summer to Arizona to see the Grand Canyon etc. I am concerned about two things, fuel economy and overheating. Can anyone give me some suggestions on things I might do to increase the fuel economy and keep the heat down. I will be traveling with my kids so the last thing I need is to break down in the middle of nowhere.

Thanks in advance.

Increasing gas millage, make sure tires are at max. pressures, fresh oil, basic tune up (if not already done) spark plugs, wires etc.

Over heating, could have a mechanic flush the cooling system but do it well before trip as I have seen water pump failure a short time after flush.

I would be nervous driving a vehicle that age with that many miles on a long trip unless it has been well maintained with good tires and spare.

In addition to the pints brought up by jimoto, you might want to replace any hoses or belts that are more than five years old.