While this topic is ongoing, you might want to check the ignition coils. When they get hot, and are weak, under load they tend to cause the engine to drop power like crazy. When they cool off, it is almost like nothing was ever wrong. I had this problem in an old Ford pickup at one time, it drove me crazy. I replaced component by component until it was fixed. I would never have put it together otherwise. I even checked the coil, it was producing spark, but after the fact, I realized it was an 'orangish' color as opposed to the bright blue that you should be getting.
I don't know if ours are oil-filled or just epoxy-resin, nontheless, it could be an element. It's just a thought, it could be 'one' of the many things that you are looking at. Good luck, Brandon
