Rob, I used these keys on LA and a 91 360 - the year before magnum, and they work on both cams - the nose is the same.
I don't think that the "magnum keyway" that the dealer looked up and says is no longer available would be any different from the stock keyway that fits from 64 - 91 cams with 'snouts'...
I know this because Hughes sent me a magnum cam without a snout when I told them I wanted a snout. They said that they didn't have the snout one in stock, so they sent me a magnum cam without a snout and then their under-designed, piece-of-****, band-aid "snout extension" for an extra $30 instead of sending me the proper cam. I had to fix their snout extension and grind a custom key way from a longer one to make this set-up work. That is why I won't buy from Hughes any more....
