I looked at Rigor Mortis at about 1300-1500 that year we got the huge blizzard in March.
It was scary V+. It was so fast and violent. It looked like it would wash you through but it was so violent that you couldn't predict what would happen if you got out of your boat. If I remember right, the wicked hole on the left was still a factor. The big rock at the bottom was pretty much under water. I heard that some pro ran it when it was close to peak and got trashed and their boat got folded up and smashed and they got their ass kicked...but that is just heresay....probably just a story made up by all the people who stared at it and took pictures....I didn't see anyone running RigorMortis, the Narrows, or BlackRock for about 2 weeks during peak that year. I'm sure that people did, but I know there were not too many takers.
I swam the narrows that year at around 1000 and it was fucked. I haven't swam BlackRock at high water (thank god) but I think that would be the worst one because it stays continuous for a good distance when it is high. I think it rates a solid V above 1000 because swimming the whole thing might kill you. I like to rate them on how bad the swim would be