Many years ago, I saw a profile of a properly packed hub in an old service manual, may have been for an International Harvester M...it clearly showed that the hub grease did not fully fill the hub cavity, but rather formed a grease layer from the hub seal to the hub bearing grease cap. From the C-1 shop manual:
I added the red lines to show the boundary layer that I have described. Once the bearings are packed to flush out any old grease and contaminants, the hub bearings are placed in their seats which should have a thin grease coating applied, then the hub seals are installed. Grease is further applied to fill the cavity between the hub seal and the inner hub bearing, with grease applied to the lip groove to displace moisture, dirt, etc. With the outer hub bearing in place, grease is applied (I use an old butter knife) into the center cavity, using the hub bearings inside diameters as a gauge. Thin layers of grease are applied to the spindle shaft and shoulder to displace moisture, then the hubs are installed to the spindle shaft and adjusted. The grease cap has grease applied in the reverse cone profile with that butter knife as shown; this grease will find its own level once it reaches maximum sustained rpms. This now continuous layer of hub grease can flow a little, and that little air gap around the spindle allows for some thermal expansion without building pressure to blow out that hub seal.
How many ounces is that? Dunno, as long as that grease layer profile is met, then that should work. I have found that modern lithium wheel bearing grease starts to dry out around the 10 year mark. During hub inspection, this can be seen as jagged cracks in the grease, something that cannot be done with fresh grease. The old grease may feel slick, but if the grease cracks, that means it no longer flows smoothly and is becoming chunky-style...time to clean out the old and slather on the new 🥳