From what I have seen, the largest kings seem to be the Southern examples of the Chain L.g.getula at over six and one half feet...and some of the Fla intergrades. I have seen a Brooks that was 6'2".
A comparison of 2' or more was not the criteria.
My response came when someone suggested that a snake could only eat another snake up to 3/4ths of it's body length which is wrong.
An 8' rat snake I think would be too big a meal for a king. However, it would not stop a 6' King from killing it (yes kings are that much more powerful. Think Retic vs Anaconda, with the king being the anaconda)
Florida Kings are not the smartest thing in the world (I have collected and kept hundreds through the years as I live in their range). Kings tend to grab first and figure out the rest later. But they are perfect crushing machines, so it is brute power vs the more skillfull but weaker ratsnake. I think it has more to do with the Kingsnake having a huge appetite and not much brain going with it. We joke down here about the kings being the "Hound Dogs" of the snake world.
The only snake threat to a large king is the Indigo. And that is only because Indigos have amazing jaw power.
Frank
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"The luxury of not getting involved departed with the last lifeboat Skipper..."