Hey Moterheads... scb400 question

[dubya]

I bought a sbc400 from a '76 van (I think) that was rebuilt before I purchased it. I bought it out of this guys garage with most of the parts. I finally put it in my truck and got it running (I go through spirts of interest), but the oil pressure is below my liking (measured at the port by the distrib). When cold it's running about 60lbs of pressure, and when it's warm it's running about 25-30lbs. Now the rockerarms sound pretty clunky, and when I remove the oil filler cap I don't think I see "enough" oil on the rocker arms. I took off the valve covers and rev'ed er up a couple of times and oil barely seeps out of the rocker arm. The valves are adjusted adequately, and I'm pulling about 18-22" of vacuum (RV cam).

Couple of question:
1) do you think the cam berings could be installed backwards?
-if possible; can I use a long drill and make my own like a ford?
2) are there oil galleys that I could have missed plugging?
3) please don't tell me dry/noisy rocker arms are the norm :-) (I "believe" the lifters are pumping up adequately, but I'm not sure.)

Other possiblilities?