return line set up

[KB Camaro]

Currently, I have a -8 feed and -6 return on my EFI set up. I'm planning to swap back to a carb, do I need to replum the return to be a -8?

[CliffsBlueCamaro]

The guys at Aeromotive have told me that you can never have too big of a return line. It should be equal to the feed line or even bigger.

Since knocking down and controlling your fuel pressure to the carb will be even more difficult, I would switch your -8AN to the return and the -6AN to your feed.

[Notalent]

I think you will be fine. Most people get away with a dead head setup with an electric pump, the -6 will only help. I run a -8 with a dead head system on a 496CI 675HP engine with Pro Systems 953CFM carb on my 496ci with a Mallory Comp 140 electric fuel pump and really have no issues at all the last 7 years...Rarely if its hot out and im idling than floor it and have to back off real fast the fuel will spew out the vent tubes, but other than that no issues. I however am in the process of adding the -8 return line as well to keep that fuel cooler.

[CarlC]

What pump does the car have? Are you trying to reuse the EFI pump?

[First Bird]

I run a Comp140 pump with 8 supply to a carb and 6 return. Was worried when I built it, but I wanted to convert the 3/8 SS supply line to a return. After build I tested back pressure at the regulator and it was 3 psi. Works great. No problems.