I have a Holley 4165 that I rebuilt for my 318. I am not having any luck with getting the car to start. If I pour gas into the engine or hit the accelerator pump 3-5 times, I can get the car to start, but it shuts off after a second and will not refire unless I hit the accelerator pump a few times. The electrical seems to check out (brand new wiring harness modules, coil, timing light flashes when turning over) ect.). I can see some fuel coming out from around the base to intake so I am assuming I need a new gasket. Is that really enough ofa vacuum leak to cause it to not Idle at all?