Mine was just above 50 at idle then going well over 60 at WOT. Thats the purpose of having the fuel pressure regulator on the rail. Its like an opposite adjustment for manifold vacuum pulling fuel from the injector. In boost, pressure goes above 58 to compensate for the extra pressure needed to flow the same amount of fuel to the pressurized manifold.

 

I wanna say my fuel pressure was at about 52 with 14 inches of vac. I can't remember where it was with boost, but with the vacuum hose pulled off the regulator it should have gone to 60.