I had a friend who thought "Dirty Deeds"'s lyrics were, as opposed to "Dirty Deeds, Done Dirt Cheap", were "Dirty Deeds and the Thunder Jeep" - Like some sort of action hero called "Dirty Deeds" who drove around in the Thunder Jeep saving the world. He has a very active imagination.
I thought it was "Thunder Chief" the first time I heard it. I'm still not sure if it's about a hitman or a bisexual gigolo. I suspect both (though admittedly trying to find a double meaning in some of the lyrics, like "Concrete shoes, Cyanide" is probably a stretch). I haven't seen or heard any stories about AC/DC members hiring the latter but that would probably be easier to keep secret! ETA: Wrote this before watching the "Done with Sheep" video. I see someone else had a similar thought.