As it looks to me, if you buy a timing set, and throw it in at straight up, and you don't need to turn the cam to get the chain on the sprockets, I would have to say you bought a 72-79 timing set. If you bought another set and straight up required turning the cam clockwise to slip the chain and sprockets on, I would say it's a 68-71 spec set.
Come on, doesn't anyone here have a Cloyes or similar timing set for 68-71 that has installation instructions for 72 and later 460's???
Mark