All good info.. I had read this comprehensive article as well as the one by simply connected and used those and others as guides in going about this.
It seems pretty clear from this article that the largest designed-in leaks for FE are the cumulative leaks in the rocker pivot area, even assuming both the rocker system and all other components are within spec. And with any excess wear or clearances in rocker system, the amount of oil that can go through them far exceeds what is required.
In the chart it shows 40% of total leak area is the rockers and down to 3% with a .070 restrictor. I went a little more at the .109 which is about the same passage diameter as a Holley 90 jet. Happy medium?
My new aftermarket set has the bushed rocker arm so shouldn't bleed off as much as those with needle bearing fulcrum and I will check to see what the clearances are before I install them.
I have built a few earlier Y-blocks with the solid lifters and those were notorious for inadequate rocker arm oiling. After looking at the FE in depth, it almost seems like Ford over-compensated for that issue with the 292-312 motors when designing the FE.