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Mechanical Fuel Pump For 1965 Shelby

Discussion in '1965-1970 Shelby Mustang GT350 & GT500' started by grm, Jan 12, 2008.

  1. grm

    grm Member

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    Hi folks,...I'm still looking for a 3939s fuel pump for my 1965 Shelby. Haven't found anything yet. Any more ideas or people that I might ask?

    Greg
     
  2. shelby6t5

    shelby6t5 Well-Known Member

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    If it is simply for the look, you could use a 3911s, the only difference is the second spring.

    There are other CABbureTER pumps that look very close, if not exact - the main issue being the arm.

    Mike
     
  3. grm

    grm Member

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    Hi Mike,...Thanks for the imput, but that's one of the problems...Can the "single spring" handle the high RPM's...in 6,000 range? I was under the impression that I might have a starvation problem and therefore engine miss...

    What do you think?

    Greg
     
  4. zrayr

    zrayr Well-Known Member

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    I'm using a '65 style canister pump (non Hi-Po) on a basically stock 289 Hi-Po engine. I hit 6500 rpm regularly w/o any fuel starvation issues. ymmv.


    Z. Ray
     
  5. grm

    grm Member

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    That sounds great! Is that the "3911 S" that Mike spoke about?

    And second question,...let me give you a little background. When I bought 5S456, it had an oil cooler already hooked up. Unfortunately it is located behind the vallance and therefore not really exposed to much air.

    To install the correct looking mechanical fuel pump, I would have to re-route the oil cooler lines or remove it all together. I'm thinking of maybe just removing it as I don't think it really does all that much and they really were not "stock" on street Shelbys. What do you think?

    If I don't remove, the lines are really in the way of where the new fuel pump would go. Can you believe it!!!???...Murphy's Law at every turn!

    Greg
     
  6. zrayr

    zrayr Well-Known Member

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    no, the pump I referred to is just a stock '65 289 pump. Not the "button top" type which has the outward appearance of the Hi-Po pump.

    about the oil cooler: the '65 GT-350 R models did have the oil cooler w/ the external lines, etc. and didn't appear to have any issues with the fuel pump interference with the cooler lines. Nice photo of that set-up in Tom Corcoran's book "Shelby Mustang".


    Z. Ray

     
  7. grm

    grm Member

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    Thanks Z.

    Are you reffering to the one pictured in Tom Corcoran's Shelby Mustang book (I'm assuming that you have a copy since you referred to it in your last post)...pg.45? Is that the stock '65 type???

    Thanks for the help!

    Greg
     
  8. zrayr

    zrayr Well-Known Member

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    on page 28 was the photo of the '65 GT-350 R model with the oil cooler, etc.

    Z. Ray
     
  9. Bob Gaines

    Bob Gaines Well-Known Member

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    This what the correct pump looks like. The correct 3939S sells in the 700.00 to 1200.00 range for NOS if you can find one . I have used cores but the problem is no one presently rebuilds this type. I hope this helps.
     

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  10. grm

    grm Member

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    Bob,...Thanks! Now I know what the "2-springs" looks like. I'll keep searching, as I'd like what the car came with...

    Greg
     

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