Good/Bad Experiences when changing to 3/8" fuel line & sending unit?

Fuel and Air Systems

  1. HMBCUDA

    HMBCUDA Well-Known Member

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    Q:What has your experience been with the New 3/8" fuel sending units available these days?

    I've found only one (so far) made in No. America,(from Bouchillon Performance)....all others seem to be made in Taiwan or China. Not liking the idea of putting in something made over seas.

    Q: Any good experiences with some made in Canada/USA that I haven't found yet?

    The guy that is going to help me with my upgrade is suggesting I change my fuel line and sending unit to 3/8".

    I have a fairly mild 340, and didn't think I need/want the 3/8" line/sending unit, but he said he pulls the sending unit any time he welds on a car, so it's coming out anyway.

    ALSO...I asked about if I should buy one with a 1/4" return line. He told me No, they only complicate the system.

    Q: What is your experiences with a return line? Good/Bad?

    Thank You for any help with this issue!
    Dan
     
  2. cpearce

    cpearce Well-Known Member

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    I used a 3/8 unit from Spectra. The only issue I had is the locking ring that comes with the new unit is too thin and does not put enough pressure against seal. This results in a tank leak, many on here have experienced this. Save your original lock ring and use with new unit. Once you see the two rings side by side you won't believe difference in thickness. I've not used return line. My fuel gauge still works correctly, others on here have had them read incorrectly with other new sending units.
     
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    • dano

      dano Evil Handy Man

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      The 3/8" steel line I bought needed some massaging and didn't fit super great. I replaced mine because someone had hacked in an electric fule pump and it was rusty. My pickup was a Sprecta as well and I experienced what cpearce did. Just reuse your stock lock ring and be sure it has been turned to enough to seal. I didn't do that and had a leak. Good luck finding much USA made and frankly, some US made items are not the quality of 20-30 years ago. Some Spectra is made in Canada. I find more issues in the poor design of replacement parts than the actual build or material quality.
       
      Last edited: Jan 7, 2019
    • 1969383S

      1969383S FABO Gold Member FABO Gold Member

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      I Used the 3/8 Spectra and the original lock ring. No fit issues at all but blocked the return as just a carb. Also used a full 3/8 line set from In-Line tubes all the way to the carb. No issues with gauge readings at all.
       
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      • HMBCUDA

        HMBCUDA Well-Known Member

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        Cool, Thanks Guys!
        Bouchillon mentioned they get their units from SPI in Montreal,Quebec Canada. Googled that, but Sprecta came up, must be the same company.

        Theirs only comes with a 1/4" return line outlet. I will have to cap it.

        Year One has one with out the return, but have not gotten a response yet from them on where it's made.
         
      • HMBCUDA

        HMBCUDA Well-Known Member

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        Thanks Gerald, I was thinking Inline tube for the line, sounds like you didn't have a fit issue? Looks like the Spectra gets the vote for pick-up unit! as long as i use my ring. :)
         
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        • 1969383S

          1969383S FABO Gold Member FABO Gold Member

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          Just a little issue installing one clip where it rounds the logintudal “Rocker” frame then up the outside of the frame at the rear wheel. Little paintence and finally got it.
           
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          • Mattax

            Mattax Just the facts, ma'am FABO Gold Member

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            I tried 3 3/8 StSt replacement lines. Only the third properly fit the '67 Barracuda and had bends that weren't ovalized in cross section.
            Sending unit did not leak but this was before the rash of problems reported here and on moparts etc. However the pickup and resistance winding is not the same as '67. In my car, the oriignal sending unit was worn out, and the original fuel line had internal rust and pinholes over the axle. Even like that it was running just around 14.0 in the 1/4 Fuel pressure would drop to zero near the finish. 5/16 original in good shape will be fine for stock 340.
             
          • HMBCUDA

            HMBCUDA Well-Known Member

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            Thanks Mattax, is that Stainless Steel line Co? =StSt
             
          • Mattax

            Mattax Just the facts, ma'am FABO Gold Member

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            I went with stainless steel for the rust resistance. The 3/8 diameter wasn't neccessary but I didn't know that. Generally there's no disadvantage and in theory advantage of slightly easier for the pump. Only disadvantage is maybe a little more time exposure for the fuel in the line to the heat off the pavement.
            Finelines's had flat cross sections and they just took it back. They had no interest in the details so I just sent it back.
            Classic didn't fit right. I think there was a change between 67 and 68 or 69 in the routing and clip locations.
            Inline was pretty much OK.
             
          • Mattax

            Mattax Just the facts, ma'am FABO Gold Member

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            Oh you posted mild cam, not stock 340.
            That 340 I was running had a Comp cams 280H, and would run just under 14.0. Its best was 13.77 and 99.5 mph with 24" autocross tires and 3.23 rear.
            Looks like I changed fuel line and pickup in '04. So those drag strip runs with the old 340 were with the 5/16 line and pickup.
             
            Last edited: Jan 7, 2019
          • HMBCUDA

            HMBCUDA Well-Known Member

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            Very good, Thanks!
            I'm temped to post my cam specs, (on another post), not sure if its good/bad/or ugly, Ha! Probably some chebby cam! Installed back in '80! (Crane Blazer cam), don't think I want to know...(head in sand) ;)
             
          • Mattax

            Mattax Just the facts, ma'am FABO Gold Member

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            My point was if the engine is running around that in the 1/4 mile, a 5/16 line will not be a restriction. Probably could get into the 12s on it without issue.
             
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            • rumblefish360

              rumblefish360 So close, yet so far away FABO Gold Member

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              Hey Dan. I have had a 50/50 with a accurate sending unit. A few didn’t work out of the box at all. Once I get a accurate working unit, which can be a pain, I follow up with stainless repop lines all over. I like to stay around the stock set up. A return line was used on a lot of the older cars. It takes stress off the fuel pump and the carbs needle and seats.

              Plumbing the return line is no harder than installing the main line and I did both at the same time, physically togther. That is how I did mine.
               
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              • daves66valiant

                daves66valiant 68 Dart 340/727:66 Signet Vert 340/5spd: 68 D100

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                Mild 340. Went with 5/16 stainless from inline tubes. If Hemi and 440s run it I’m fine with 5/16.
                 
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                • HMBCUDA

                  HMBCUDA Well-Known Member

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                  Thanks for all the responses! I appreciate you all taking the time to share what your experiences were. I ended up going with, (bought) the 3/8" sending unit and lines after the guy helping me with the build mentioned today that "even ford 289 mustangs came with 3/8" lines", figured at least i'll have a larger line for future HP up grade if needed some day. (and return, if i want to plum that in the future)
                   
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                  • HMBCUDA

                    HMBCUDA Well-Known Member

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                    update...Well got what I paid for I guess... DSCF4601.JPG DSCF4599.JPG MADE IN MEXICO....NOT CANADA...:/....insert gun to head immogy...hope it's not crap... DSCF4600.JPG enough said.
                     
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