My motor is happy 10-14 at idle and between 36 and no more than 38 degrees total advance. I run a modified Ford Duraspark distributor, removed the vacuum advance and welded the advance slot to limit the advance.. There are some really good posts on the 460Ford.com website about setting them up.... There is a vendor over there that explains exactly how it's done. He sells units he modifies for $50 bucks. I don't think I have ever checked my timing at idle since. Just run the motor up set total to 38 and lock it down.
http://www.reincarnation-automotive....ons_index.html
Paste this and go look, this guy knows 460 motors.
John