I also tried the ground wire and the oil pressure gauge still is dropping, I changed the fuel filter and it is idling a little better, I plan on getting some new vacuum hoses tomorrow and replacing all of them and getting a mechanical oil pressure gauge and trying it. While I'm at the store I will pick up some thicker oil and a filter and try changing them if the gauge doesn't take care of the problem. I live in Michigan and don't drive the car during the winter so I'm not too worried about the thicker oil.@BKM48198
I added a ground wire for the oil pressure sender, and it didn't change anything.
The next possible culprits are the wiring , dash connectors,and the anti-slosh/instrument voltage regulator module.
My gas gauge hasn't worked correctly for months, so I guess it's time to fix the spare anti-slosh/instrument voltage regulator module that been sitting on my electronics workbench for a very long time...