Fuel return line ideas for '67 camaro

[paco1112]

I have a '67 camaro and I was looking at putting Retrotek BOSS EFI on my LS364. However the EFI system recommends a fuel return line for motors over 500hp. My fuel tank and sending unit are stock '67 parts and are brand new. I do not have an option with my sending unit for a return line. Does a '69 sending unit have a return line? Can I self tap a return line directly into the tank? Since the tank is brand new I don't want to change it for an after market. I would like to work with it.
If anybody has come across this or has any suggestions please let me know.