I originally did both feed and return with 1/2" Aluminum line and AN fittings from Speedway.
Aluminum Fuel Line, 1/2 Inch O.D.
Fitech says not to use aluminum line, but the Speedway stuff has a thick wall and can handle up to 250psi. I recently replaced my feed line with ptfe stainless braided 8an 'cause I needed to re-position my fuel pump nearer my sump but I still have the aluminum return line.
