Drilled crank?

[jeepguy1948]

So, I just bought a freshly rebuilt “B” motor (with weighted crank). I was told that it had a “drilled crank” I ham some idea what that means but I know that I could learn more here. In addition, I’m wondering if it would still be a good idea to oil that center main direct or if that is taken care of by the drilled crank. BTW it is using Babbitt (which sort of disappoints me because I can’t replace the bearings myself but I doubt that they will need replaced in my lifetime LoL)