My opinion: Cross drilling is a lot of work, and weakens the crank. Using full groove main bearings will get the same results.
PS: what difference does it make if an auto trans or not?
As for upper engine oiling. It is not necessary to drill the oil passage larger. Just cut a small groove all the way around the rear cam journal (on the cam). This will give full flow oil to the top end, instead of "pulse" oil. Don't make the groove very deep or wide. It doesn't take much.
