O, by the way, good choice on the car (68 2000)!
And low oil pressure (at least according to the factory gauge) is very common with the U20 engine. In reality, it's about 5 - 6 lbs. at 700 - 800 rpm. As soon as you bring the idle up a little (900 - 1000 rpm), it should jump up off the zero on the gauge.
But in the end it was an easy fix. Just a little tired from 17+ years as a daily.