Have a question about a Ford 460.....

I am thinking about getting a 86 F250 from a friend and there is a couple issues with it. He was driving down the highway at 55mph when he heard a pop and a large cloud of smoke roll out in the mirror. The thing went through two quarts of oil in about 40 miles! It now blows the PCV valve out of the valve cover and blows oil out the dipstick tube. My first thought is that it dropped a valve and jabbed a hole in a piston. That is the only thing I can think of that would put that much pressure inside the engine block. Can anyone support my theory or give me any other possibilities to check. The truck is free if I want it so I could justify fixing it, but dont really want to put a new engine it when I already have a truck that needs an engine overhaul.