oil pressure gauge all over the place

[1991SSP]

swap on 1996 silverado5.7 to 4.8.. used lextech's information and kept the original harness and repinned for the 411 pcm... oil pressure has brand new sending unit... the gauge at idle is way past 80,, when the engine is revved or driving pressure goes to normal... tried another sending unit and also tried another cluster with the same results.... any suggestions?

[1991SSP]

Issue solved,,,, went through a couple of BWD sensors from advance.... they were all bad.. installed a GM sensor and it fixed the issue....