Automatic to 4 Speed swap,...How hard????

Discussion in 'Transmission & Driveline Topics' started by Vet76te, May 14, 2010.

  1. Vet76te

    Vet76te Veteran Member

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    I have a 1981 Z28 with a newer 350 crate motor and the factory 350TH transmission.

    I want to chnage it to a manaul transmission.

    Has anyone done this swap?
    How difficult is it?
    How much should I expect to spend on the conversion?
     
  2. brooksman9

    brooksman9 Veteran Member

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    Fancy meeting you here.
     
  3. brooksman9

    brooksman9 Veteran Member

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    I'll give you a hint

    [​IMG]
     
  4. badazz81z28

    badazz81z28 Veteran Member

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    Very easy, the first thing I did when I bought my first 78Z. The biggest PIA is the cutting part. Other than that, everything is a direct bolt in.
     
  5. Mwilson

    Mwilson Veteran Member

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    took me less than a day but I aquired all the parts first and had everything ready
     
  6. Cardinal

    Cardinal Veteran Member Lifetime Gold Member

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    $2000 to $3000.

    Muncie or Borg Warner T10 transmission.

    11" SFI flywheel

    Clutch kit: 11" clutch, pressure plate, throwout bearing.

    Bell housing (I would recommend a Lakwood SFI bell housing but an aluminum will do if you don't plan on racing it) THINK SAFETY FIRST!

    Clutch fork.

    Clutch cross shaft and mounting bracket on frame and ball on engine.

    Link from cross shaft to clutch fork.

    Link from cross shaft to firewall? or link from clutch pedal to cross shaft? I can't picture in my mind's eye how that linkage goes!

    Clutch and brake pedals (car with automatic transmission has a brake pedal that is too wide to clear clutch pedal).

    Shifter (get a good Hurst Shifter--don't skimp on this!).

    Drive shaft loop.

    Heavy duty U-joints.

    Spare drive shafts, U-joints, axles, and transmissions another $2000 or $3000.
     
  7. BondoSpecial

    BondoSpecial Veteran Member Lifetime Gold Member

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    I have converted 3 F bodies so far back and forth between manual and auto, I can never make up my mind. I'm thinking about doing it yet again. There are advantages of both. The hardest part like was said, is the cutting, other than that it's just parts swapping.
     
  8. anesthes

    anesthes Veteran Member Lifetime Gold Member

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    Wha??

    For 3k I can do 3 cars.

    -- Joe
     
  9. anesthes

    anesthes Veteran Member Lifetime Gold Member

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    Depends on how 'perfect' you want it. On mine, I was redoing the seats and painting the car, so the carpet was coming out anyway for painting. So I cut the floor and welded an OEM manual 'hump'. Cost me maybe $15

    I bought a few transmissions, because they are cheap. I have a spare saginaw
    which cost me $100. I've been told never pay more than $150 for a sag.

    The pedals, linkage, etc all new aftermarket is under $200. Like 175 maybe. Buy new.

    I get my clutches from fort wayne, have for 10 years. He makes me cheap dual friction clutches that hold 500-550hp no problem, for under $200 to my door. My 11" clutch with ceramic on the flywheel side, organic on the pressure plate side, with a blowproof pressure plate, was $165 to my door with a throwout bearing.

    I use a timken roller pilot bearing, around $12

    Flywheels are cheaper than poo now. For a STOCK STREET CAR, a nodular iron flywheel is around $100. Don't run a cast iron flywheel.

    You can get a SFI approved billet flywheel for around $150 all day, however most run a thinner .640" distance from the crank hub requiring a race clutch disc with smaller, or no springs. (bolts will hit).


    The shifters are expensive, a good hurst fetches $150 on the forum, or $200 new. (go figure). Summit makes a 'decent' shifter for around $119 with new linkage. I have one of those.

    The driveshaft, cross member, is the same as your TH350.


    Bell housings are another thing. You can get the fancy Z28 bell housing for $250 on the forum, or $300 new. Or you can get the thicker, stronger, truck bell housing that nobody wants for $0-50, and just put the adapter ring in it for $25.. As pointed out, again for street use. After seeing, hearing about many clutch explosions for competition use, or on a hot car a $300 scatter shield is a good idea.


    One would argue the Saginaw will eventually explode, and doesn't shift as well as a Muncie. Agreed, but rather than spending $800 on a stinky Muncie, if you want a nice transmission put that money towards a TKO.


    It can be as cheap or expensive as your goals.

    -- Joe
     
    Last edited: Jun 8, 2010
  10. 77nomad

    77nomad Veteran Member

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    The hardest part really. I used a piece of firewall from a four speed car in the junk yard as a template to locate where the hole must go. Just bolted it to the master cylinder studs.

    [​IMG]
     

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