Reworking the 273 Adjustable Rockers

The increase in hole size from .100 to .125" is about a 50% increase in flow. But it is not just flow.....it is a matter pressure too if you want these holes to physically squirt the oil over onto the springs and retainers. Personally, I would stick with the .100" for this reason. You are adding a lot of flow outlets in the shaft now, and will have much greater outflow area than just with the standard rocker oiling holes and grooves. My concern would be with the level of oil and pressure in the shafts dropping too much.

I agree on ditching the head flow restrictor IF you are not using the full flow cam bearings or grooved cam journals. The flow area of a .080" diameter restrictor is about .005 sq inches.... which is only around 1/10th of the area of the standard LA design flow restrictions. If you are using the full flow cam bearings or journals, then I would expect some restrictor is in order to protect the mains.

FWIW, the flow restrictor makes more sense if you are using roller rockers in some circumstances; those do not have the same flow restriction at the rocker that the standard shaft rockers do.