I went to replace the line and 5/16 wouldnt go on so I tried 3/8 and it went on with as little persuasion
Huh?
3/8" is larger than a 5/16" line. Are you sure you don't have the sizes flip-flopped? If you had to persuade anything, I'd assume the other was fitting too tightly? Or are you talking about placing rubber on a steel line?
Just so everyone knows, the only cars that I know of that run 3/8" line from the factory were 440 6, Hemi and Maxwedge cars, along with 3/8" pickup tubes into the tanks.
The vent line that runs to the front of your car, straightlinespeed, is a 3/16" vent tube and it will spill fuel if left installed, without running above the fuel tank level. That's why it's capped. Someone took the charcoal canister off that it used to run to.
I wouldn't suggest capping all of the lines. You should have at least one vent line, or you can kiss the paint on your quarter panel goodbye on a hot day. Urethane clearcoat paint is fuel resistant, but basecoat is NOT.
And depending on how well the fuel neck port on your quarter panel was prepped before paint, as well as how carefully the neck was installed, if fuel surges and finds it's way under the clearcoat from a crack, even near a screw hole, it can terrorize the paint all the way down to the bottom of the quarter panel and lift the basecoat, as well as everything on top of it.
I had to repaint the quarter panel on a magazine featured '59 Dodge 6.1 hemi that had this problem, when it was at the car show in the pits of the Mopar Nationals at Bandimere on a hot day.
The best you can do is trace that 3/16" line back and put a small inline filter on top of the tank, from a rubber hose.
For your fuel line;
I run the zinc plated soft line from Napa. It comes in a roll that is loose enough that when you begin openning it, if you flex it by hand in larger sections, it will straighten up. I work on trim at my shop, so I'm used to getting things super straight, but it's way easier to work with than stainless.
The double flaring tool that they sell works just fine with it. I would suggest oiling the mandrel and cone, as well as the threads on the compressing clamp for clean centering and operation. If you do that, it will give you a lot of service and even work well down to the 3/16" lines if you ever want to make your own brake lines.
Sticks are always nicer to work with, but you can get very nice results out of a roll if you keep from unwinding it in shorter sections. If you pull on it, do it as wide as you can and think about getting it straight from one end to the other, rather than in sections and it will look sharp.
Think of the double flare fittings like heat shrink tube on a wire and put them in place before putting any bends in the line, so they are trapped at the flare. I also use the mandrel with the cone to put half flares in lines that need rubber going to them, from the car to the engine, etc, so the clamp has something nice to form the rubber line on.
I also use a hand held tubing bender like this one -
There are better ones out there, but this one has given me show winning results and it was cheap. I tip the line about 5° and then walk the line about 1/8-1/4" up and continue. If you don't, it can put a slight kink in the line, but if you go at it slowly and move the line through the bender in small incriments like that, it will give very nice results.
Just use your old line as a pattern. If I have a complicated bend, I'll tape where I want the bend to start and stop, then mark on the masking tape where I want the bend(s) clocked.
I just finished making 5/16" solid line for my Street Demon and rerouted the line to get it out of the heat soak area of the heater hoses and upper radiator hose. I'm a fan of solid lines anywhere I can get them in, because they don't require looming and tons of organizational fasteners like soft lines will.
