AFRacer is right. Im running twin 40s and a holly red top and regulator the holly is self-priming so it doesnt matter where it sits. I have set the regulator at 3psi at idle and it creeps up to about 4 1/2psi (i think, ill have to check) and it runs fine. what fuel lines are you running? the standard are way to small and you'll need to replace them.