The cam lobes are generally oiled from "splash". The Cam BEARINGS are force feed with
oil pressure, as are the lifters (if their hydraulic anyway). The rocker arms are force feed also. The result of all this
oil "flying and splashing" around provides the bulk of the
oil for the cam lobes.
That why you got to keep the RPM's up fairly high with a new cam setup, to make sure the lobes get "splashed" until the lobe and the lifter are happily married.
You can wipe out a cam lobe VERY quickly if it looses for even a short while. Pre-lube is good, but not a "killer" deal. After the engine starts and oil pressure comes right up, your all right.
The BIG question is: Just because you got oil pressure READING doesn't mean you got oil pressure INSIDE the motor where you need it to circulate!!!
Plenty of stories about blockages occuring AFTER the pressure gauge and the motor starving for oil with 75 psi showing on the gauge!
Ernie