You know, I was just thinking about what you said about closing the hood.
I don't know **** about the electrical systems on any car, but don't foxes come wired with the one courtesy bulb built into the hood underside? I know that my 1986 Mustang had one.
I remember cause when I removed the insulation, the wire came loose and I was worried about it getting caught in the belt or something. So I cut it and sealed it off. You said that it ran fine, but as soon as you shut it, it went nuts? That's the only thing I could think of that would allow for an electrical change if nothing happened until you shut the hood.
Is it possible that wire shorted something? Just a wild guess off into the blue yonder, but I'd like to do whatever I can to help you get to that dyno on Saturday.