Those are the published numbers. Bill Buckley posted to rec.roller-coaster last Spring three completely different numbers that allegedly came from Stengel himself, where 122 degrees was the smallest of the three. I don't remember what he said they were, though, and with DejaNews off the air, it's kind of hard to check.
I suppose the best way to find out might be to visit the park when there are Science Day activities going on and take a sighting across the rails...
Just remember to add 90 degrees to the measurement!
--Dave Althoff, Jr.