I'm going to add a second port near the front, going into the same boss as the fitting I just added. It'll be 1/8 NPT though. I'll probably drop it in the left galley in the middle...I don't think it will matter much where I put it but I guess a middle position is most 'central'.
The fittings are Yor-Lok (SwageLok) type that are rated for 3000PSI. We use these at work....they seal and never leak.
I haven't seen much on the three tapped bosses above the center three cam bearings, they are used for the factory 'spider' that holds the hyd roller lifters in place. They have to be plugged or they'll be big oil leakers. I'll probably use two of them to attach some braces to help secure the oil lines and reduce any vibrations.