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67 GT350 Drivetrain Mods

Discussion in '1965-1970 Shelby Mustang GT350 & GT500' started by KMan66, Jun 22, 2011.

  1. Jun 22, 2011 #1
    KMan66

    KMan66 Member

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    I have 67 GT350 #2355 currently with the rebuilt original 4 speed Toploader and 3.89 gears. I was investigating overdrive alternatives and heard the Tremec 5 speed requires extensive modification to the floorpan. The Keisler Engineering 5 speed, as per the company, only requires a dollar size piece of hump be modified. I am now looking at the Gear Vendors attachment that gives midrange gears between all original ratios plus a 5th overdrive gear. It attaches to the tail end of the original Toploader and requires a new, shorter, driveshaft. Any input on these three options would be appreciated.
     
    KMan66, Jun 22, 2011
    KMan66, Jun 22, 2011
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  2. Jun 23, 2011 #2
    roddster

    roddster Well-Known Member

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    You heard wrong. You might have to shave some off of were the shifter comes up through the floor but installing a T-5 into a 67 Mustang is pretty routine.
     
    roddster, Jun 23, 2011
    roddster, Jun 23, 2011
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  3. Jun 23, 2011 #3
    KMan66

    KMan66 Member

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    Thanks for the info roddster. I am happy with the response of the 4 speed off the line, but on the top end I push over 3000 rpm at 70mph on the highway. Not fun at that point. An overdrive mod is in my near future and I will certainly entertain the Tremec 5 Speed. I've heard nothing bad about them.
     
    KMan66, Jun 23, 2011
    KMan66, Jun 23, 2011
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  4. Jun 26, 2011 #4
    zrayr

    zrayr Well-Known Member

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    For me, keeping the four speed was an important factor in keeping the character of the car firmly rooted in the 1960's.

    My solution for many years was to install a 3.00:1 rear end gearing to lower cruising RPM's. Then I added about 75 HP via a vintage Paxton to restore acceleration.

    Z.
     
    zrayr, Jun 26, 2011
    zrayr, Jun 26, 2011
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  5. Jun 26, 2011 #5
    KensKR

    KensKR Well-Known Member

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    I've read that the 6spd. requires a lot of tunnel modification to fit, but the 5spd. is an easy installation.
    I have a friend that has a Boss 302 with the gear venders overdrive. He loves it.
    He uses a Hurst T handle knob that has a line lock button to engage the overdrive.
    Kenny
     
    KensKR, Jun 26, 2011
    KensKR, Jun 26, 2011
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  6. Jun 26, 2011 #6
    zrayr

    zrayr Well-Known Member

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    zrayr, Jun 26, 2011
    zrayr, Jun 26, 2011
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