Hey RickD,
75 PSI at 3000 RPM with
oil not up to operating temp is not a dangerous high pressure 75 PSI at 3K RPM with
oil/engine at operating temp is not a dangerous pressure either but it may be more than your engine needs.
Possible harms from a Too High
oil pressure are many and can range from burst oil filters or lines, breaking oil pump drive or hurting the bearings with worm like channels eaten out of the surface. The oil bypass may open bypassing filtering or not suppling engine. It takes horsepower to create oil pressure and more for high pressure. All this is way more than 75 PSI though.
Too much oil or to the point that the crank whips it into a froth is of course bad but the average amount of surface area in a pan help that from happening but.... Depending on how lines are run and height of everything in relation to the sump level of the oil pan can be misleading. I had one car built so the oil would run back from a cooler and the filter and and lines so it would read about 2 quarts over full if you allowed enough time for it to drain down. This was not a Cobra and needed a check valve to stop it from drain all the lines. If you checked the dipstick before drain-back it was just right. It was too low with the engine running when filled to full line.