[mr0077]

Ant, in Pat Ganal's book ("Ford Performance"), he comments that the NASCAR crank (C9AZ-6303-D) is "...recommended by Ford for continuous 7000-9000 RPM use (just in case thats what you intended)." That tells me that if you build the rest of the motor right, the side oilers for sure, and probably all the 427 blocks, are good for at least 6000-7000 RPM continuous use (if that's what you intend).
Street cruising at 4000-5000 should be no problem (for the motor, not sure about your ears, etc.).