My rb20de-t 64 barracuda

Most of the engine harness is wired in now. I was going to start on the fuel system, turns out the tank is missing (I never checked it before) but the filler neck is there. So now I need to figure out if I replace it with a stock unit, or fab in a more modern tank. I have a couple different fuel tanks laying around. Once it has fuel it will be ready to run.