to the front of the car i know that one is fuel pump, one must be vent to charcoal canister whats the third one. Im intalling a holly sniper set up with intank pump. i need to run a return line to the tank. if one can be used as a return line that would save time and money 1975 buick park avenue/ electra with a 455
The third line is the fuel return. On a 1972 Electra the fuel feed/return lines go up the passenger side and the charcoal canister line goes up the drivers side. Bear in mind the Sniper wants 60 psi fuel pressure so if you are going to use existing lines they had better be in good condition. Any external corrosion could cause a blow out if it's weak enough. Bob
Pretty sure its in good shape. Down in nc. But ill check if they are surface rust free. So that's good news. I don't have to run a return line then. Should make install quicker
I would not use 40 year old lines that were not installed for EFI. Its gasoline under 60 pounds of pressure...expediency should not drive your decision.
Yeah - I'd advise against using the existing lines even if they look OK. There are places where they run up over the rear suspension you just can't see. These were one of the worst spots for corrosion on the lines I removed when I did my conversion. As far as handling the pressure. The mechanical pump sucks fuel from the tank so there is minimal pressure on the feed and return lines and relatively low pressure from the pump to the carb. If you use an in tank pump you are asking the entire feed line and Sniper to pressure regulator extension to handle 60 psi. And that's from the moment you turn the key on until you turn it off. Also the feed and return lines route to the mechanical fuel pump so you'd have to make extensions from there which would mean making up hard line extensions with adapters or swaging for rock solid flexible extension lines. Not relishing the idea of spraying some unseen part of the underside of the car with fuel at 60 psi was one of my main reasons for replacing everything end to end Cheers Bob
You can use nylon or nickel copper. Both are pretty quick to install and will never rust from ethanol / moisture.
