I purchased a cloyes double roller timing set 9-1122 for my 460. I will be installing soon and I am still trying so figure out how to set it up for straight up timing. The engine is 1986 and the timing set is for 1972 and later. It is the set with three adjustments 4 deg retarded, 0 deg, and 4 deg adv. (three different key ways) Which key way setting will get me to pre-72 straight up timing?