1995 Dodge Van tried everything you said.... still cuts out

I am very sorry for all the frustration your van has been causing you. I will relate a couple of experiences I had with my vans.
If you open the hood, if you can think of it as a little hood, you'll see the harness, a few had shorting problems there, you could just grab the wires, in the center, it could turn the engine off.
The vehicle speed sensor would also kill power at highway speeds intermittantly, no codes. The reason for the electronics in diagnostics is especially important if your having this type of problem.
I hope the computer that runs your engine can pick-up any last wire and that wires circuit is usually the last thing it reads, giving a technician a starting point. Many friends also had problems with VSS's. Hope it helps in any small way. Can you read it(engine comp.) for codes? You'll get it, and when youi finally get it fixed, you'll have experience money can't buy.