fuel regulator?

i have a non by pass regulator on my 440 now with two carter carbs, here is the issue i left the non bypass reg in place but oppened it up to use it as a fuel block for the two carbs...i also added a by pass regulator with a return to the tank. turns out the fuel sending unit has a 1/4 return that i plumbed my 5/16 0ld fuel line to with a brass reducer, an added a 3/8 main fuel line. after getting the holly blue pump going i can only get it down to 9 psi...i need to make the return at the sending unit bigger...but was wondering what would happen if i used the other reg to bring the pressure down until i can fix the return fixed.