Race car enignes in the past ran 4 retarded pretty commonly, but I never saw any feedback on trying to drive one on the street with that. They also probably took the time to measure the cam's valve events. Guys like EDC and probably others cam doctored numerous stock cams to get a "good" one. They varied significantly.
I know a Factory Stock racer very well and with the cam rule it makes it a whole new ballgame. Before it was grab 50 stockers and see what they do... now its grab 100s of different cams and see what each does and what it does to the RPM range. Needless to say my friend already has a good 300-350 dyno pulls this season playing with cams!