Moly rings should seat with in minutes, The cam needs 20 minutes at 2500rpms unless its a roller. After that start beating it. Parts dont get stronger with use.
If the engine goes on the dyno first you dont need to worry about it.
I agree with this. The old 500 mile deal was because machining tolerances were horrible back in the day. I will go out on the freeway and do the 40 mph in high gear routine.
Lots of my cars got the cam broken in, oil changed, and a 7000 rpm burnout as first duty. Roller cams didn't get 5 minutes of run time before getting hammered on.