The #2 port is the output to the rocker arm shaft- - - -it gets there via the copper tubing that transits the block through the water jacket. It does not connect to the main and cam bearing oil galleries at all. The hole in the block you asked about is on the output side of the oil distributor- - - -the only time it receives oil is when there's sufficient pressure in the main and cam bearing passages to push the spring loaded plunger off its seat. This setup prioritizes oil flow to the lower end of the engine- - - -shutting off flow to the rockers whenever there's a pressure drop in the main/cam bearing circuit- - - -idle, and/or excessive bearing wear. It's like the human body's circulatory system- - - -sacrificing extremities to keep blood flowing to the body's core. Rocker arms don't need a lot of oil- - - -just enough to keep a thin film of oil on the bottom of the rockers is plenty.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!