walbro external fuel pump and wix corvette filter/regulator

[87squarebody]

I'm helping a buddy with a 5.3 Vortec ls swap on a 85 c10.We have a 85 fuel tank and are using the walbro 255 external pump and the Wix 33737 corvette filter/regulator.We put a fuel gauge on the fuel rail and just hooked up a power and a ground to the pump and the fuel press pegged the needle on the gauge over 125psi.Shouldn't the fuel pressure regulator keep the pressure at the rated 55to60 psi.It is all brand new im thinking we have a defective regulator or are we over looking something.Thank you guy in advance.