I don't think you need two regulators. You can use a high pressure regulator up by the carb that drops the pressure from 60 psi to 6 psi. You will need a full length return line. The nice thing about a setup like that is if you buy the correct regulator you won't need to touch the system if you ever switch over to EFI. Just screw in the adjuster and you'll have 43 psi at the injector rails.