Lots of folks have their biases on whether Chevy, Ford or Dodge made the best. That's the wrong focus. When actually, each of them has previously at some point made BIG bad mistakes.
The question really is,...is this motor design one of those mistakes?
The answer is no,...this is one of the best turbodiesel motors ever made.
Others may attack this and say another is best. So what?! The point is that if it has been taken care of, and if you take care of it as well,...these 7.3 liter Powerstroke motors are known to be very reliable and live a long time.
One of the key reasons yours will likely live a long time (assuming it is in good shape) is because as a t444e, it was produced in a reduced horsepower version from what the Ford trucks received. Ford boosted them to 275hp in their trucks, but International/Navistar designed them for only 215hp in commercial applications, which they called the t444e. As a result, the t444e put even less stress and wear than its sister motor, the 7.3 Powerstroke. Ford fans call this the "Million Mile Motor", because it truly can (when taken care of with regular maintenance) last that long.
Don't let the fact that it has only 215hp instead of 275hp give you reason to fret whether it can do what you need it to. Unless you are towing a heavy trailer, the t444e will haul a heavy living quarters built-out version of your step van just fine. For instance, many Snap-On and MAC Tools step-vans were loaded down with thousands of pounds of tools and tool boxes with this motor and drove around all day, every day, just fine and performed well.
The next generation Powerstroke motor (the 6.0 liter from 2003-2008) is the problem child that gave Ford headaches and has soiled the reputation. And the 6.4 that came after that (2008-2010) was an even worse train wreck of an engineering disaster. But the 1995-2003 7.3 Powerstrokes are solid buys, with the 1999-2003 being the best.
Now nothing is perfect, and the 7.3 Powerstroke/t444e does have failure points that tend to be where trouble occurs most often if trouble occurs at all. But no more often than, say, a Chevy Duramax motor or the legendary Cummins. But no matter which diesel motor you end up with, they ALL leak oil. That's just a fact of life. The 7.3 Powerstroke/t444e does tend to be a bit more leak prone than some others, but that's a minor sticking point.
I was expecting to find my van with a t444e, but ended up finding a Chevy Duramax powered model for a screaming deal price I would be stupid to not take advantage of. But if I had instead found the t444e Ford van I was expecting to find,...I would have been perfectly happy.