Slant 6 Turbo 68Dart Project

filter before the pump is good. is it the clear kind that you see if its clogged or not? filter wouldnt keep the fuel from flowing backwards but a check valve would. the bowls see the same pressure as everything else in the system. if the boost pressure is higher then the fuel pressure its gonna push the fuel out. what are you running for fuel pressure? if you are only pushing 5psi boost try 6psi fuel pressure. the holley should be able to hold it. run it with the hat off just to be sure before you go driving it.

if your boost reference on the regulator is good (hose isnt blowing up or leaking) and your lines are clear there isnt a whole lot left. its a pretty basic system. i would look for collapsing lines before the pump. its gotta be something simple.

its a shame you dont live closer. i would love to help you figure this out in person. planning any east coast trips soon? lol.