I verified that the pump is not starving for oil.  I cleaned the suction screen, replaced the entire suction hose and clamps, then tried pressurizing the reservoir slightly.  I am guessing 5 psi, didn't want to starting blowing out seals....   only added about 200 rpm to the fan, bad noises remained.  

So, by process of elimination, it has to be that the pump is not rated for that RPM.  Vickers literature I referred to may not be specific to this pump, but I think it is.

Only thing I haven't done is put a guage in the pressure line before the valves and see if the restriction of the valves is really substantial.  There is a 1" T I could use, once I get some more fittings.