I'm a natural pessimist, lol. This way I am never disappointed.
I went out and looked at the hardware. Someone's been there before and reinstalled the stuff incorrectly, I believe. They have the conical castellated nuts installed on the four outer INTAKE manifold studs, with the cone facing out. The four outer EXHAUST studs have the washers in them, but regular nuts. If I understand correctly, the conical nuts and associated washers go together and on the four outer EXHAUST studs?
I found an NOS source for the funky nuts, maybe. Frank Mitchell, fmmpr on Ebay. I sent a question asking if he had the washers, too. We shall see. Though to be honest i haven't heard good things about him over the years.