fuel pressure too high

I'm trying to get this car started but found a major fuel problem while checking for leaks. fuel was pouring out of the carb a few seconds after the pump turned on. kept messing with the carb (needles,float, o-rings) and got the leakage to slow enough to check fp. it was 12. geez! got it adjusted down to 9.5 before the adjustment screw came out. I'm wondering if this is a regulator problem or maybe a fuel line problem. the goods: fox, carb conversion. sumped tank to an aeromotive 11106 in-line pump, #8 all the way up to the reg, aeromotive 13301 bypass style. #6 x2 to the two carb inlets and a #6 return back to the stock fuel pump assembly. no pump in tank, just using it to return. any ideas? the reg is supposed to get down to 3psi so i'm a good 6.5 over . can the fuel line i'm running cause that much pressure increase?
thanks for any help !

actually the aeromotive pump is for carb or efi. their website does not give flow rate but says up to 700hp efi, or 900hp n/a carb. i'm also using the recommended aeromotive bypass regulator. they do recommend at least #8 return and I have #6 going back. it just seemed like a huge pressure increase for it to be too small of a return line. on the other hand, the car is not yet running and that is the only place for the fuel to go, besides pouring out of the carb.