Upgrading the fuel tank

He does mention a return line in the original post. I have an EFI pump and regulate it down to 5psi and have a return line that bleeds off excess pressure, so it definitely can be done. I also have a Gen 2 hemi that had Fitech F.I. on it and when it crapped out on me I put the 2 four barrels back on and ran it like that for a year. So the regulator does work for F.I. and carbs with the lower pressure. Just adjust it.