Keep it going!!! Keep the fluids changed. I think that has a whole lot to do with how long it will last. Oil, Transmission, Radiator I'd say are the most important along with clean air and fuel filters. There is also rear differential fluid that will keep your rear end gears good. It depends on how much and how often you carry a lot of weight to how often you should change that out of the ordinary usage change. I have my favorite fluids change place in Monroe, Michigan if your within a couple hours of there I think the drive will be worth it, for transmission fluid change. Magic Quick Lube. They know what their doing.
My million mile van finally died. I then got a 2003 E-350. It was a very nice van...and then I rolled it on I-75 in morning rush hour traffic at mile marker 1.6 - 1.5 southbound.
Now I have a 2006 E-350 Super Duty. Just last week I now have 250,000+ miles on it and running strong.
I really should work on updating this site with pictures of my new vans. I just haven't done it yet.