I was a plumber a few years back. Volume and Pressure are two different animals, people tend to wanna increase their water pressure in an attempt to overcome galvanized piping being nearly internally closed off due to being almost rusted shut, or to overcome their improperly sized piping (copper/ pex/ pvc).
Do you still have a return line outta your fuel filter?
This would be my 1st test/ attempted fix
A separate regulator for each carb might give you more volume, just jacking up the pressure on just one regulator (feeding 2 carbs), may not make up for decreased volume trying to push thru the regulator's internals.
I bet the mechanical pump woulda provided enough fuel! But I'm guessing!
If you are experimenting, maybe increase the fuel line size from the pump on.
I have a Holley 390 on mine (pic above)
Images (Click to enlarge)
Saturday, August 27th, 2016 AT 5:50 PM