Besides his Mach and the requisite Chevy engine swap, nothing comes to mind other than (2) 4.6 swapped cars. I think one of the 4.6 cars owner is looking to swap to a 5.0 Coyote in the near future? Otherwise I am drawing a complete blank. Oh, and the old Sudden Death II with the 460(?).....
While not exactly a swap in the full sense of the word, I recall seeing a propane-powered II up at Carlisle one year, many moons ago. Must've been before I had a digital camera since I don't seem to have any images on my PC of it...but I definitely remember seeing that.