All this talk about oil pressure reminded me that my sending unit never worked for me. I rebuilt my engine 4 years ago and added a HV oil pump, I know I didn’t need it but sounded good at the time. I also replaced the sending unit with the proper 67 289 unit but it never would read pressure. I have since replaced it two more times each time the gauge would work at first then stop. Is the stock sending unit only good for low pressure? If so what sending unit could I use to replace it? I will be changing out to Autometer Gauges soon so I am sure that will fix the problem but I have always wondered what was up. Thanks for your time.