I was searching the forums but was unable to figure out what is going on with my 350. It was very cold the other day (like -20) I tried to start her up but she was turning slow. I threw the hood up and noticed she has pushed engine oil out around the filter from the cranking, oil was 10w-30. Since then, I changed to 5w-30 and my oil pressure is near zero at hot idle. As soon as I touch the gas it jumps up to about 40-45. It starts cold at about 50-55. When I rebuilt the engine, I used a Z-28 sping in the oil pump and have not plugged the oil filter adapter. I use the AC 35 filter. I installed a mechanical gauge thinking the old electric one was the problem, but the pressure is the same. I am leaning toward the relief valve in the filter adapter, any thoughts?