CAUSES? High oil pressure
I run Z-alt 20/50. Do yourself a big favor and pick-up an after market Oil Pressure gauge,hook it up and see what it reads! I just lately installed oil/water gauges in my Cuda because with my new motor I was getting worried because my factory water gauge was over the top when at idle for a while.The after market gauge reads 180 max! Old gauges might not be so reliable anymore. Just my opinion..