Well, just when you think you have everything licked....
I changed the oil tonight and found no issues with it. It came out looking good, the filter looked good and the magnetic plug didn't show a single sign of any metal. I refilled the engine with the 15w-40 that I was using, and with the breather off, I started the engine and watched inside. I couldn't see ANY oil flowing. I checked the other side and saw the same thing, no oil flowing. I went ahead and pulled off the valve cover and started the engine again. Again, I couldn't see any oil flowing. On the off chance I made a mistake putting the wrong rocker stand bolt in the wrong location, I pulled the proper bolt out and saw that it was the necked down bolt that it should have in that place.
I have no idea why this is happening. With the engine warm, there is just a tiny, very tiny, amount of oil getting to the pushrod. It's not even enough to run down the pushrod, or fill up the bottom of the head. And normally you should have oil being shot at the valve tip and running down the valve spring, and I'm getting none of that. There is literally no oil pooling in the head at all, and I can rev the engine with the valve cover off and not get a single drop of oil thrown anywhere. If there were a plug that came out in the upper passages, I don't think there's any way I'd have the good oil pressure that I have. I can't imagine that the oil passages are plugged, but given the crud that was in the engine, that may be a possibility.
At this point there's nothing I can do. I either scrap the idea of going, or run it and hope that the cam and lift is mild enough that the valve springs will survive and that I don't destroy the valve tips or rockers. I thought about going back to 10w-30 oil in the hopes that the thinner oil might flow a little better. I might change the oil again in the morning before I take off.
I'm open to any and all suggestions, although I don't see a remedy for this except for possibly thinner oil. It was 90* here today, so it's not like the 15w-40 was real thick either.
Edit to say THANKS for everyones good wishes and support!