I've been doing a search for a while and all I can find are threads talking about people running 3/8 return but never mention what the stock one was. What is the stock return fuel line size? Also If I run a bigger supply and return line and reduce it back down at the pickup tubes on the tank will it sacrifice some flow. I'm not to concerned with the supply line. The minimum recommend supply line for my pump is 5/16. Which from what I gathered is the stock supply fuel line size. Sorry for asking questions that probably have been asked a million times before.

 

im pretty sure the stock return line is 1/4".

right now im setting up a surge tank w/ 3/8" feed and regulator return lines for my turbo project, and then retaining the stock 1/4" line for the surge tank -> fuel tank return... im hoping that the little return will be enough to vent the surge tank so as not to cause excessive fuel pressure w/ my efi pump

 

i just went turbo and ordered a bigger return from summit (3/8 i think) and put it on then went to the stock return hose into the tank and it has been working for me so far and i have a big MSD fuel pump.

 

Yeah I'm not planning on going turbo with this car. If I keep it. But the previous owner built the motor with racing beat apex seals which from what I understand are very fragile to detonation. So good 1/4 is what I was guessing. I plan to run 6an return and supply lines and take it back to rubber at the tank.

 

You should really try and find a -se pickup or do bulk head fittings. I had the stock 12a pickup and at idle fuel psi would go through the roof do to the bottle neck at the tank return side. the -se pickup has a 1/2 feed, and 5/16 return, the-se hard lines are 5/16 and aeroquip makes compression fittings to attach -6an.

 

How much pressure where you trying to run? I'm planning on running 6psi. From what I've read that is what is recommended for Holleys.