Rear Gear Ratios V8 vs. 6

Discussion in 'Technical' started by Drew Hierwarter, Jun 13, 2015.

  1. Corbin Johnson

    Corbin Johnson Member

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    All my V8 cars came with 3.00:1.
     
  2. rthomas771

    rthomas771 Member

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    The 71 4-door V8 parts car I had was a 3.00
     
  3. Krazy Comet

    Krazy Comet Tom

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    My '72 is V8, A/C, P/S etc has factory 3.00... The '71 200, 6cyl with no power options has 2.79 ...

    I suspect the V8 std transmission cars has deep enough 1st gear that 2.79 was more the norm...

    A check of the posted Marti reports would tell what ratio it came with, have one for a '72 GT with V8, 3-spd and no power options that has 2.79...
     
  4. Acornridgeman

    Acornridgeman MCCI Wisconsin State Rep Moderator Supporting Member

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    Well that shoots my theory on V8 cars. Guess it is just a Ford thing .......... :)
     
  5. Ronald Hopkins

    Ronald Hopkins Member Supporting Member

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    All air conditioned cars that I ever saw came with a 3:00 rear gear.
     
  6. Acornridgeman

    Acornridgeman MCCI Wisconsin State Rep Moderator Supporting Member

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    I just looked through some of the Ford shop manuals to see if they indicated a pattern as to why Ford used 2 ratios and I couldn't find a thing. Even the early 7 1/4 came in 2 ratios - 2.83 and 3.08
     
  7. Acornridgeman

    Acornridgeman MCCI Wisconsin State Rep Moderator Supporting Member

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    Everett - is you door tag there yet? If so, is the axle code a 3 or a 6?
     
  8. mojo

    mojo "Everett"- Senior Citizen Supporting Member

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    I will have to check it to see. I have to bleed the brakes, just put on new master cyl. I will look when I do the bleed soon.
     
  9. joerockne

    joerockne Member

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  10. Powerband

    Powerband Member

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    here's some more for the crew:

    My : '71 170 3OTT = 2.79 - 4 lug

    '74 250 3OTT had the 2.79 - 5 lug

    '76 200 C4 2.79 - 5 lug

    No AC on them

    Maybe a DSO thing??

    hav e fun
    [​IMG]
    . [​IMG] .

    [​IMG]
     
  11. Krazy Comet

    Krazy Comet Tom

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    Nope, 3.00 considered "Performance Option" & included with A/C(exc 250). Option price $11.66

    For '72/'73, these were norms expected
    .
    170... No Automatic or A/C option, 2.79 std.(170 discontinued for '73)

    200... All options avail, 3.00 with A/C, 2.79 without.

    250... '72 Automatic ONLY, 2.79 with A/C, dunno if 3.00 would have been opt. Std trans aval in '73.

    302... All options, 3.00 with A/C, 2.79 without.
     
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  12. joerockne

    joerockne Member

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    They would have ran a lot better with a 3.40 gear or so !
     
  13. Powerband

    Powerband Member

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    They would have ran a lot better with a 3.40 gear or so !

    By the 70's, the typical speeds traveled had crept up to 'interstate speeds' and higher off hiway as well. The dominant trannys Auto, 3 & 4 spd stick were still 1:1 final ratio. Without Overdrive capability the mfg's including Ford simply raised there rear axle ratios ( lower numerically) , to be able to keep the same 50's and 60's motors from hi-rpm related MTBF ' problems and dismal MPG. Earlier cars with same engine/trannys typically did have lower geared ( higher numerical) ratios.

    hav e fun

    [​IMG]

    '
     
    Last edited: Apr 11, 2021
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  14. bmcdaniel

    bmcdaniel Senile Member

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    My late '70 with the 7 1/4" rear and manual trans had 3.08s.
     
  15. Krazy Comet

    Krazy Comet Tom

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    Until the FE big blocks(332 & 352) were introduced in '58, the highest ratio(low number) was a 3.10, with std trans & overdrive having up to 4.11. With plenty of torque the 352 got 2.69 rear gears. From that point onward most automatics had 2.75-3.00. Six cyl engines maybe up to 3.25. Was a different story for std trans, my '64 Galaxie 289, three on tree had 3.25, while the 3-speed 390 drivetrain from another '64 had 3.50 (swapped everything from that car to mine). At 75 mph the '90 was a screamin, but never fazed me a bit. With same gear in my Cobra, gas pedal "buzz" would numb my foot. For a trip to TN in Y2K, I swapped to a 3.00, makes a much nicer highway cruiser.
     

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