"..Kip Keino, who ran 3:34.9, the equivalent of a 3:42 sea-level mile...Keino's performance has to be considered as the greatest 1500m of all time."
- Lore of Running. Tim Noakes, MD
It should be noted, Jim Ryun did rip a 3:37.8 (3:46 mile at sea level). Not to shabby. He later on went on to break the 1500m record of course. Had he run with proper pacers(like the GP meets of today), 3:29 would have been his for the taking, maybe Keino going sub 3:29.
These are the true kings of the mile, pre-epo days.