return line to gas tank

[Stowe, Ted-SEA]

hi.

I'm just about to go out and find a shop to do some light brazing or
welding, to add a fuel return line to my mgb gas tank. I bought a used
sender/fuel line unit, so I could take the fuel line off that and add it to
the existing one in my car. before I do this, are there any rules about fuel
return lines ? other than don't point it at where the float would be sitting
?
I am trying to minimize the surprises/features.

thanks, Ted Stowe