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.