2000 Monte Carlo SS proper fuel pressure?

Your fuel pressure is regulated by, as you’ve seen, a fuel pressure regulator. To check the pressure, you’d want to know the pressure with the regulator regulating, and with it not regulating. Not regulating might be considered the raw pressure the fuel pump is capable of supplying, as compared to the pressure the regulator regulates to.

The “pressure while cranking” might be more appropriately called “unregulated pressure”. You can measure it by simply removing that which operates the regulator, which is engine vacuum. If you remove the vacuum hose, the regulator is rendered inoperative. It’s much simpler though, to just measure the fuel pressure with the ignition switch on but with the engine not running or cranking. Just turn the key on, don’t try to start the engine, and read the pressure. The pump will only run for two seconds or so, so read the pressure quickly. If you miss it, turn the key off and try it again.

As for regulated pressure, as you’ve seen, just read it with the engine running. If you have 45 psi with the engine running, I’d suspect you have no problem with fuel pressure. If you can’t find what the pressure should be, you haven’t tried very hard. Check a Haynes manual for what your running fuel pressure should be. I’d guess 45 psi is plenty.