Having done any number of long hauls, I'd say "It's not the best idea". Since we don't know a lot about the trip, it's difficult to take in even the common variables - how many people, how much gear, all interstate - or not?
Although my wife and I both have 'newer' cars; for long hauls when we can't fly, we usually rent an unlimited-mileage car from one of the 'big' rental companies. You can probably get a comfortable small car for around $175 per week with all fees included.
You'll get much better gas mileage
It will be recently serviced and have good tires
The heater and air conditioning will work
If it breaks, they'll bring a replacement to you
It will almost surely have a decent stereo and you won't feel like you're driving inside a base drum...
The Econoline is 24 years old and most of the parts (and electronics) are probably 10+ years old
Just my two cents...
SL