I used the factory style hard line, Hemi sized 3/8 supply and bought a regular BB/SB 5/16 line for the return and ran them side by side. I flared the factory line with the GM push-on style o-ring fittings and bought the appropriate adapters. For example Russell Performance 644133.
AG.
General rule of thumb is that the return line should be no less than the diameter of the feed line.
I agree100% !!!!! but others will say you can use 1/4 in return
Yes I guess that would be me
Used a 1/4 return on a twin turbo 70 malibu with a 255lph walbro pump for years.
I think the general rule of thumb applies more to carburetor setups that are trying to regulate down to 6psi. Hasn't been an issue for me with efi pressures.
