Chrysler Repair: drop in oil pressure, oil pressure sender, chrysler new yorker

Question
I have a 1988 Chrysler New Yorker with a 3.0 Mitsubishi engine.  It has good oil pressure when engine is first started, but as engine warms up, the pressure drops to nearly zero.  There does not seem to be any excessive wear on either the main or rod bearings.  There is some variation in the measurements of the camshaft journals, about .005 from low to high.  All else seems to be OK, including the oil pump.

Answer
Hi Stan,
What do you mean by low? The gauge reading or a calibrated pressure gauge attached at the oil pressure sensing unit hole? The minimum pressure requirement is 6 psi at idle, and 35-75 at 3,000 rpm. What weight of oil are you using? Increasing the weight one step may be helpful. If the calibrated gauge reading is acceptable then you may want to replace the oil pressure sender. Does the oil pressure warning light come on? These are factors and measurements that you may wish to consider.
Roland