Got a chance to look at this again. Evacuated, pulled a vacuum for an hour and recharged with 1.5 lbs of R134a. I got a scale and weighed so I was sure I charged with the correct amount. I also made sure I purged the yellow gauge line so air didn't in.
Results: low side pressure oscillated between 25 to 28 PSI, high side oscillated between 135 to 150 at around 750 RPM. The pressure oscillated at a rate of about every 2 seconds and the high and low sides changed in sync. Ambient temperature was 80F, duct output temperature 90F
Static pressure equalized after 15 minutes or so to 100 PSI, both sides. The large line out of the evaporator coil into the dryer/accumulator was warm and the small line into the condenser was just barely warm.
Is the pressure oscillation an indication of a problem? Seems like the high side pressure is a bit low according from what I am reading here.