It's okay to not know everything. The 216 is a 14 pound pressure engine as evidenced here:
http://chevy.oldcarmanualproject.com/shop/1948_51truck/51ctsm0648.htmAll of the babbit splashers I have ever seen are 14psi at 2000rpm. The Oil Distributor is what controls that as well as the small tubes and orifices. Since the oil pumps pressure relief valve doesn't play into it, Chevy could use whatever they want I suppose.
In the later model years post 1955, the 235 was measured at 1650 RPM (30psi) so that explains why some of us here think that the oil gauge builds up slowly and goes up and down with rpm. (Full pressure engines behave differently because there is no oil distributor, the oil pump controls the pressure directly.)
I am awaiting this real world information. I am known for doing testing and providing real world information, so you can see where I would be all ears. You will have to overcome the deficit of starting off thinking Chevy's actual manual has it wrong, but I will be as pleased as everyone else if your testing gives us new insight.
