Muncie swap to modern 5 or 6 speed

Discussion in 'Transmission & Driveline Topics' started by Cooldawg, Sep 30, 2016.

  1. Cooldawg

    Cooldawg Veteran Member

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    I'm trying to pin down costs on a potential engine & tranny swap for a 1971 4 speed car with a shift console. The car presently has a 350 small block.

    I'll just do the engine of it requires any drilling or cutting. Probably go with the blueprint 383 (430/450). Like the warranty and don't have any experience to draw upon to put one together myself. Also plan to keep the existing 3.73posi rear end.

    I've heard a lot about the Tremec TKO five. The top gear would be a heck of an improvement over the 1:1. Is there a kit that would not require perminant mods but still place the shifter where it needs to be? I figured several folks have already done this upgrade.... Based on what I've read on the site already, I'll probably have to shorten the driveshaft. I can live with that, if necessary.

    Also noticed most of these have a lower 1st gear. Curious about the trade offs there as well as R's at highway speeds. Thanks!
     
  2. BonzoHansen

    BonzoHansen Administrator Lifetime Gold Member

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    If you are buying new TKO kit I'd suggest reaching out to hurst drivelines. With a 3.73 rear i'd look at the 600 with the numerically lower first gear.

    Another option is the LGT 5 speed. For that just call Jody http://jodystransmissions.com/ That might be a direct bolt in, not sure exactly.
     
  3. Cooldawg

    Cooldawg Veteran Member

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    Thanks. Sounds like I need to take a chill pill. The LGT5 looks like a great candidate, but they don't have a crossmember- yet. Said they should have one within the year...

    The TKO's require mods according to the Hurst folks.
     
  4. BonzoHansen

    BonzoHansen Administrator Lifetime Gold Member

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    Ask Jody, you might be able to use a stock xmbr with the LGT
     
  5. grzewnicki

    grzewnicki Veteran Member Lifetime Gold Member

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    The 3.73 is definetly to low of a gear for the first gear in the 500, you end up with a 13:1 final ratio, you want to be 9-11, trust me I learned the hard way and had to swap out my 3.73 for 3.42. The only cutting I had to do was a little elongation of the shifter hole (back/right side cut out a half round piece so the shifter boot on the TKO could come up. I used my old cross member by cutting off the mount, shortening it, re welding it on a bit higher. I had to modify the mounting holes in the ends so the cross member could sit back a little farther. Pics are all in my build thread. Richmond also makes a 5 speed overdrive: http://www.jegs.com/i/Richmond-Gear/836/7020526B/10002/-1 the first gear ratio is 2.89 so coupled with 3.73 out back your final drive ratio is 10.77, a little high but still within limits, any higher and you go throiugh first gear way to fast. I'd go with Hurst drive lines vs American Powertrain, I got really crappy service from American. No questions about my final drive ration when i ordered, a piece of crap cross member that had the trans mount holes drilled in the center (factory the trans sits about 1 inch to the passenger side), they said just push the trans over...WTF?
     
  6. Cooldawg

    Cooldawg Veteran Member

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    That's why we use uni-joints, right? Insane.

    I'll have to stick with the Muncie if mods are required. Made that decision when I forked out the extra $$ for a documented car.

    But the LGT should be a nice solution once they intro the aftermarket crossmember. According to Jody, they are in the works; they had to tend to those Chevelle people first . The ratio should be pretty ideal for 3.73:

    2.66:1, 1.78:1, 1.30:1, 1.00:1, and a useful .69:1 for highway cruising.
     
  7. czizza

    czizza Veteran Member

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    The TKO-600 works better with the 3.73 ... I got the TKO-500 used with my 3.73 it is a beast out of 1st and 2nd spins more ... BTW, no tunnel issues, slight cutting of the shifter hump, bought the crossmember from SST.
     
  8. Cooldawg

    Cooldawg Veteran Member

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    Below is Quote from American Powertrain. They said no mods but hard to guarantee noting "floor sag". I'm suspicious given Grz's feedback with respect to them...

    Also pondering sticking with the Muncie and bumping the rear gear to a 3:42 or 3:08. The motor I'll be swapping in will be a 383 with considerably more torque. The rear end is period correct but I've been told it is not matching. The more I think about this idea, the more I like it.


    Transmission Detail:

    TKO600 GM Street&Strip, 26-spline input shaft, new in box, full factory warranty
    Ratios: 2.87, 1.89, 1.28, 1:1, .64
    ProFit TKO Installation Kit for 1970-74 Gen 2 F-body (Camaro/Firebird). Your
    kit includes:
    AP Revolution Shifter Mechanism - Original 4-speed shift position
    Main Case Streamlining - For additional tunnel clearance, includes billet fork cover
    Seamless DOM Driveshaft Assembly - Race Balanced, Solid U-Joints
    Driveshaft Slip Yoke - Cryogenically hardened steel
    X-Factor Cross Member - Modular Aluminum, bolt-in
    Transmission Mount - Ballistix ISO-X
    Pilot Bearing - Stainless rollers, grease pre-pak
    Reverse Light Harness - Weatherseal
    Speedometer Conversion - Mechanical or Electronic
    Shifter Knob - White
    Hardware, Instructions, Warranty and Customer First 24-Hour Support

    NOTE: Kit requires no mods to tunnel, console or carpet. White Lightning shifter
    upgrade available.

    FWCV-11004, SCIENCE FRICTION Billet Steel 153t Flywheel, 1-piece main
    seal, 1986-up Vortec, ZZ3, ZZ4, ZZ383, Mechanical Linkage
    SCIENCE FRICTION 1126 STAGE1 SUPER STREET CLUTCH KIT,
    INCLUDES:
    STANDARD CLAMP LOAD LOW FLEX FORMED PRESSURE PLATE,
    26-SPLINE FULL FACE WOVEN KEVLAR REBOUND HUB DISC,
    ALL STEEL RELEASE BEARING,
    STAINLESS PILOT BEARING,
    ALIGNMENT TOOL,
    475 FT-LB RATED,
    LIGHT PEDAL EFFORT
    SLUN-10001, 10" round stock shift handle for 67-69 Camaro and 65-73 Mustang
     
  9. stoney2677

    stoney2677 Veteran Member

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    I believe the X factor cross member is the same a buddy used when he got his lgt600. This was right after keisler went down which was a few years ago. Not sure why you couldn't use it for an lgt now.
     
  10. mickstan

    mickstan Veteran Member

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    "Requires no mods". Famous last words. I did the Hurst TKO 500 in my '78 with the 3:08 rear gears. Love it. As far as mods, yes it will happen. Tunnel will need a little cutting, nothing major. Have to have new body bushing all the way around. Driveshaft length is 47 inches center to center of u-joints, so it will need to be cut and balanced. And it gets a different slip yolk on the tranny end. I just bought mine straight from Inland Empire, ready to install, no worries. I know it costs more, but I would recommend Hurst for this. A friend went with ADL and was not happy. And just bite the bullet and get the ENTIRE big kit from them, bellhousing and all. You can keep your mechanical clutch, but get a new one, like a 11" centerforce. This is gonna cost a bit of money to do it right, don't cheeze out on it, you'll be sorry. But at the end of the project, you'll have a 21st century transmission that lets you cruise the interstates at 90. Long road trips are not a problem. Fuel cost? I got overdrive. Its a job you will only benefit from, there are no drawbacks.

    In fact, a friend has his '69 camaro in my garage at this moment getting a TKO transplant!
     

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