Jim, that makes sense so by drilling this out from .080 to .180 (rechecked the sizes) it will reduce the oil pressure to #4 main compared to the others in the even of pressure/volume loss from top end. Hopefully that doesn't happen and if it does hopefully the coated main bearings will buy me a little more time/safety.

Here are picture of the drilled out oil restrictor on the bottom of #4 cam journal and then un-touched #3 cam bearing journal (a little blurry)

That KB picture you posed must be the newer and redesigned blocks as mine doesn't have that port on the back left side (around 10 o'clock)