I got the 460 running but the oil pressure is high. Very high. It pegs the gage at 100PSI at start up and never came down. Keep in mind this is during cam breakin so the motor was always running around 1500 - 2000 rpm. This is an older autometer gauge that was in the truck when I bought it so I don't know the history there. The PCV valve is new and working and I'm getting smoke from around the breather. The motor is new and just going through cam breakin so I figured the breather smoke could be due to the rings not being seated yet. The short block was prefessionly built so I'm figuring the pressure relief is right - as much because that's not what I want this to be. Is there a way to test a mechanical gauge to make sure it is working properly?

 

best way you can tell yourself is temp replace it with a known good gauge or put it on different engine and see if it reads the same.

If you can regulate your air compressor and can put it on so it's air tight you could check against the known air pressure in your tank.