1994 E150 Misfire

I just purchased a 1994 E150 5.8H to make a cross country trip to California in about two weeks. Here is my problem as it has unfolded. I got the van knowing that there was a slight misfire in it thinking I could correct that and be done with it, but so far I have spent SOOO much money trying to track it down. Here is a list of things that I have done so far:

1.) Changed Wires and Plugs and they are gapped at 45 per the mechanic
2.) Changed the Distributer and also the Cap and Rotor
3.) Changed the Fuel Pump and the Fuel Filter
4.) Changed the PCV valve
5.) Changed the Air Filter
6.) Cleaned out throttle body and check hoses for leaks

After all of that the van had an excellent tune up and the engine always felt strong, but it didnt correct the misfire. I was driving home yesterday and it was misfiring and looping or sort of dropping in and out like it was gasping for air then it would come back. This was normal but this time it did it but then the van just stopped working and wouldnt turn back on. It was turning over but wouldnt catch. I thought it was the new fuel pump since we had just put it in the previous day, maybe there was an error or something, but after we sat for maybe 30 mins it fired back up, but now it was driving very heavy like I was only on 5 cylinders and not the whole 8. So we confirmed that for whatever reason, the Coil was not shooting out fire to the plugs. So we

7.) Changed the Ignition Control Module
8.) Changed the Coil Pack

This appeared to correct the issue and it fired right back up with no problem, however it was still misfiring but I was at least back to square one from where I started. I had all of these new expensive parts but still no answer but I thought I had some relief. I went to the store which was only about 1 mile away, a short 3 min drive up the road and back. When I pulled into the driveway I sat there for a sec iin park idling to make sure all was well, as it was doing its regular misfiring and then it gaspped again and cut off and would not start back up.
the first thoght is that its getting air somewhere but not sure where from, but the that wouldnt expalin why there was no fire from the coil.

PLEASE HELP! The clock is ticking and I have hardley and funds left. I was originally going to change the PCM (the grey box under the drivers side dashboard) but I didnt do it, should I have? Can you help?