I am trying to get a 2.0L FI running again and have soft copper which is for air conditioners. It is usually thicker wall than ordinary 3/8 in cu (for AC stuff)

It seems that SAE 30R9 is what the forum recommends.
Has anyone tried using soft 3/8 cu and then just use small 5/16 30R9 jumpers?
Will 5/16 30R9 slip over 3/8 without problems. In effect make the 3 ft runs across the engine out of copper.

My idea would be to buy the 10 ft roll SAE 30R9 5/16 off ebay for $45 and try to redo the blister, the area under the fuel tank, the risers from the ss down the rail to the upper part of the engine and then the two across the engine.

Any idea how many feet of fuel line is needed for a redo? 5/16 30R9? I bought the 5 piece SS 8mm kit to convert a 73 to a 74 type setup. Came with the 2 long picecs down the rail then two "risers"
and an adaptor (converts smaller line from tank to 8mm?)
Advice is really welcome !

No copper lines in a car. Ever. Vibration can work harden them and then they're prone to cracking.

10 feet of hose isn't enough. It takes 14 ft. plus to do just the engine and the area forward to the firewall. The hoses under the tank are 2 different sizes, BTW, and 5/16 won't safely fit over a 3/8 tube.

The Cap'n

You can buy (Jegs or Summit) Aluminum fuel line designed for the purpose. They are compatible with A/N style fittings. You can also flare the ends to use with hose.

You could buy SS lines from one of the vendors here. This is a very popular and easy swap.

Your brakes and your fuel system are two areas where you should avoid the temptation to save money.

Had soft copper lines for over ten years.
I will replace them this winter, but no cracks yet.

Rich

I think he said that he wants to get it running so why not. You should be able to slide 5/16" over 3/8"o.d. w/o a problem. Not 3/8" i.d. (or 1/2"o.d). I assume your referring to ACR or Type L soft tubing. If so, vibration won't be an issue unless you do something stupid. Like a metal to metal rigid brace instead of an adell clamp. Your home A/C vibrates much more than our 4 bangers and has copper connections. You'll need to get a beading tool to raise the edge so it won't blow off from fuel pressure. About $75 for a cheap one.

All my fuel hoses are [high pressure] rubber, and S/S lines through the tunnel. If I were to substitute the rubber hose in the engine compartment with anything else, it would be S/S tubing.