Malmo, Ryun did run the 3:58.3 at Wichita State. The track was chewed up and it was pretty warm. Back in the 70's we would do interval workouts at our cinder track and go up to KU and do the same workouts on its then tartan track. My 800's would be always be four to six seconds faster on the tartan than the cinders.
coach - having run in the late 70's, the number of well kept cinder tracks were becoming few and far between as variants of rubberized tracks were being laid. I am not sure I can recall racing on a well groomed cinder track. I lived on the cusp of the major urban area in my state and thus was stuck running on many cinder tracks - only later did those tracks have rubberized surfaces.
I once ran a late all comers summer race on a cinder track against a guy who was a future 3:51 miler. It was, as was typical, a lousy cinder track with ruts and ridges. We both gutted our way to a less than fabulous 4:28 performance, and we both thought it a decent piece of speed work in anticipation of cross country season (he was in college already). As I look back on it, though, those dinky races on lousy cinder tracks made us comfortable with simply racing, an element that put all of us in good stead later on (because the times in and of themselves didn't inspire).