1967 Sylark, from automatic, to 4-speed. Help please.

Discussion in 'U-shift em' started by Johnny Angel, Aug 16, 2019.

  1. Johnny Angel

    Johnny Angel Well-Known Member

    My friend would like to convert his 1967 Skylark from automatic, to a 4-speed. He would like to mate it to a basic 455 with a cam. It would be a street car. We are looking at using an M-20. Are clutch parts, like pedal assemblies, Z bar, bell housing, etc., interchangeable between years? Or, must we get all parts, including the trans, from a 1967 Skylark/GS?

    Any help with part numbers, advice, and sourcing of parts would be greatly appreciated.

    Thanks,
    John
     
  2. flynbuick

    flynbuick Guest

    There are threads dedicated to 4 speed change overs. Figure 3 to 4K if you are not going to a 5 or 6 speed. That will cost more.
     
    Johnny Angel likes this.
  3. flynbuick

    flynbuick Guest

    The block will need to be bored for a ball stud and the crankshaft will need to be machined and fitted with a pilot bearing. There is a thread on this also.
     
  4. wkillgs

    wkillgs Gold Level Contributor

    You'll need pedal linkage from a 1967 GM A-body. Unsure about the z-bar. Some ball stud parts are repo'd for other GM's and may fit.
    Bellhousing from 64-up Buick V6, 300/340/350, or 400/455, will fit the 455. New flywheel avail from TA Performance.
     
  5. BuickV8Mike

    BuickV8Mike SD Buick Fan

    Very doable. No.
     
  6. wkillgs

    wkillgs Gold Level Contributor

    It is very do-able! If you can find a 67 Special or Skylark parts car with the basic V6 3 speed, you can use everything except the trans and flywheel.
    When I did a 5 speed swap on my 66 Special, a $225 parts car supplied most of the necessary parts. ....but parts cars are harder to find than they were 20 years ago.
     
  7. 455monte

    455monte Well-Known Member

    I did my gs340 a handful of years ago.
    Not a real big job.but Is time consuming.
    Start with a list of everything u think u need then post it here so we can review it with you
     
  8. philbquick

    philbquick Founders Club Member

    As Walt said the 67 clutch pedal is different than a 64-66. Not sure if the 68-72 clutch pedal will work, the rest of the clutch linkage is the same 64 to 72. I once put a 340 in my 64 Special and the ball stud hole was already tapped and the crank took the pilot bushing no problem, I don't know anything about 455s. Your rear end ratio is probably a 2.78 so an M-20 with a 2.56 first gear should be OK but it will be long legged (you'll be winding it out a long time in each gear, which I happen to like). Sounds like a fun project!
     
  9. wkillgs

    wkillgs Gold Level Contributor

    Looks like the 1967 GS400 has it's own z-bar (in upper left corner). Maybe the 65-67 V6 & small 8 one will work?
    There's an online catalog at 65gs.com in the 'documentation' section. See p 138 for the below pic.
    http://65gs.com/documentation/

    The brackets, pivot studs, etc may be generic GM. Look up the part numbers and search on e-Bay. May also be able to purchase from an Olds/Pontiac supplier like Fusick or Ames.
    This page has parts and info as well:
    https://www.4speedconversions.com/67_skylark_linkage.html

    Clutch pedals are 1967-only since GM went to a larger diameter steering column that year for the collapsible shaft.

    upload_2019-8-19_13-55-43.png
     
  10. Johnny Angel

    Johnny Angel Well-Known Member

    Thank you so much wkillgs!
     
  11. PGBuick

    PGBuick Well-Known Member

    I put a 4 speed behind my AT 455 this past winter. I used Dave Kliener's repro Z-bar and ball stud in my 64 with 64-66 pedals. You should remove the driver's side fender to weld on the Z-bar tab to the frame rail. Just locate it from the assembled Z-bar and ball stud. I don't see why the pedals from 64/65/66 wouldn't fit a 67. Perhaps the shaft style is different. I've seen shafts with bushings, and big thru bolts with double bushings. The link from pedal to Z bar was a bit strange in mine. I had to bend it to make it work ( I don't recall where I got it - maybe Kleiner). Any BOP bellhousing should work. Many say the 11" clutch fits in a SBB aluminum bellhsg. Or you can get a BBB aluminum one - there are tons of them. Check the block. I think most are already drilled and tapped for the ball stud. Most AT blocks are NOT prepped for the Throw out bearing. Most are drilled and rough finished with a few turning steps in the hole. Option 1 is to custom turn the OD of a bronze bushing with a slight press fit (I think .001-.002 interference will work). Option 2 (easier) is to buy the special TO bearing from Dick Miller Racing. It is very narrow and fits in the precision machined area that the torque converter snout goes into. I used one and it's good so far. Lastly, absolutely check the bellhousing runout and use offset bushings to correct if necessary. Also, be aware that there are different height trans mounts. I needed to use a short one on mine. My trans is the M23 Autogear - so essentially same case dims as the M20-M22. Big block 4 speeds are a blast, but way, way harder to race.
     

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