Fuel System Help

you cannot use the vent line to return fuel back to the tank. the vent line is just that. a vent. you can use it IF you vent the tank another way. alot of the cars came off the production line with a vent line that ran up the filler tube on the inner quarter panel. you could make something like that pretty easy. as for the return line. you cannot run it right off the pressure regulator. your system will just create a loop and pump fuel back to the tank. you need the return line to come off the rearmost portion of the fuel rail on carb.