After 34 years, I attached an oil pressure gauge to my old shovelhead. It's sorta frivolous but Ive thought about it for years and only just now got around to doing it. I have the two-into-one header that doesn't leave enough room atop the tappet screen without hitting the exhaust. I had to fashion a few fittings and make a bracket for the gauge. It turned out to be quite a little project but it is done and works fine.

What surprised me was the pressure numbers on this 106,000 mile motor (original block). When the oil is cold and at idle it pumps up to 30-40 pounds and with a little revving it boosts the gauge upwards of 50+ pounds. When hot, the motor pushes just above 20 pounds of oil at 2500 rpm. At 3000 rpm, Im showing maybe 25 pounds. At idle, when hot, it's just below 20, maybe 10-15.