RAMMs talking about one of the oil system mods for sustained rpms. Different year engines may have different sized oil feeds from the lifter galley to the main saddle. It's standard practice to enlarge them to 9/32" with a long drill.
That's the thing--The first 2/3rds of the hole was 9/32"--I just tried the drill bit in the hole and ASSumed it was drilled that size the whole length--It wasn't. It has nothing to do with sustained RPM's. It only has to go to an rpm where oil VOLUME is inadequate ONCE to sustain damage. Live and learn--It cost me alot to learn this lesson, but my customer is happy and I haven't had any bearing issues since, so I'm happy.
p.s. Your main bearings look terrible BTW--Either dirt or insufficient clearance. I don't understand the suddeness of your low pressure though---Unless your relief valve got jammed open. J.Rob