Fuel Pressure wrong?

[minid50]

I have a fuel lab fuel pressure regulator that is reading 30 when the car is running. I disconnected the vacuum line and the FPR reads 38. Doing some searching the info states that 1G fuel pressure should be at like 34.6. Is that pressure with or without vacuum?

Also I have a walbro 255 in the fuel tank. With stock injectors.

 

[romeen]

For a 1G it should be 37psi with the vacuum line disconnected. The fuel pressure will drop 1psi for every 2inHg of vacuum when the line is reconnected.