Can you use a B body stock sending unit in an A body gas tank? If so, you could get the Hemi style sending unit for the gas tank that has a sending and return line provision. Then, use the Hemi fuel filter/canister that has a return line.
I have this on my Road Runner now. You could then put an external fuel pump back by the tank.
Keep in mind that this is mostly Cliff Clavin style theory.
