- 1964-1967 SP400 Parts Images
- How to wire the Switch Pitch on a Buick Transmission
    - 400 auto codes
- BOP Bellhousings and Automatic Identification
Results 1 to 9 of 9

Thread: ST400 S wap for ST300

  1. #1
    Join Date
    Dec 2018
    Location
    Longview,
    Posts
    5
    My Feedback

    (0% Positive Feedback)
    Rep Power
    0

    ST400 S wap for ST300

    I have a 1964 Riviera with a 425 nailhead and ST300. Since this is a one-off year for this tranny, I have been contemplating a swap. My current plan is to use a 1966 ST400 (code BR).
    Now the questions. Is this a direct swap or will I need to modify the cross-member or driveshaft? Can I use the smaller torque converter from my ST300?

    Iím new to the forum and to the intricacies of these cars.
    THANKS

  2. #2
    Join Date
    Aug 2001
    Posts
    1,553
    My Feedback

    (0% Positive Feedback)
    Rep Power
    19
    The 64 Riv had a ST 400, but it was not a switch pitch like the 65-66 Nailhead ST 400. They are dimensionally the same size and bolt in the same location using the same mounts. The fixed pitch converter from the 64 ST 400 will not work in a later ST 400. The wiring will also be different. You will need the stator idle switch (for stator positioning at idle) and detent/stator switch (for downshifting and stator positioning under load). These can be found on any 65-67 Buick with a ST 400 or ST 300. You would just need to adapt then to your car using the same brackets or modifying them.
    Steve B.



    67 GS 525 Buick Stage IV
    66 GS Convertible
    65 GS HT
    63 Riv
    02 Subaru WRX Turbo
    03 Ford Cobra Convertible (Factory Supercharged)

  3. #3
    Join Date
    Dec 2018
    Location
    Longview,
    Posts
    5
    My Feedback

    (0% Positive Feedback)
    Rep Power
    0
    Thank you for the info. I will track down the switches and get it hooked up. I think that this will be a big improvement over theí64 setup.

  4. #4
    Join Date
    Dec 2018
    Location
    Longview,
    Posts
    5
    My Feedback

    (0% Positive Feedback)
    Rep Power
    0
    I may be in a padded room before I understand this transmission. I have purchased an ST400 out of a Ď66 Wildcat 401. Code is BR so all seems good. This transmission was on a dolly when I bought it and the torque converter was separate. How do I identify the tc as a switch pitch? I donít see any markings on it.

  5. #5
    Join Date
    Apr 2004
    Posts
    4,813
    My Feedback

    (0% Positive Feedback)
    Rep Power
    0
    check out Larry's post on this page:
    https://www.teambuick.com/forums/sho...a-GS-%29/page2
    The way to crush the bourgeoisie is to grind them between the millstones of taxation and inflation.
    Vladimir Lenin

    Government schooling is about "the perfect organization of the hive."
    H.H. Goddard, Human Efficiency (1920)

  6. #6
    Join Date
    Dec 2018
    Location
    Longview,
    Posts
    5
    My Feedback

    (0% Positive Feedback)
    Rep Power
    0
    Thanks,
    This is just what I needed. Iíve now confirmed that the TC is switch pitch and Iím ready to get it installed.
    I think (hope) that I understand the wiring needed to complete the swap. Really looking forward to the improvements over the Ď64 transmission.

  7. #7
    Join Date
    Dec 2018
    Location
    Longview,
    Posts
    5
    My Feedback

    (0% Positive Feedback)
    Rep Power
    0
    Another question regarding the switches for this tranny. The switch on the drivers side is correct with 2 blades set at 90*. I understand that the top (horizontal) blade is is for the SP stator. Iím looking to use a 3-position toggle for it. The vertical blade is for the kick down. I have attached a pic of the kick down currently on my Ď64. Will this kick down work with the SP? If not, should I just get a B&M?
    Finally (?), I am having the trans swapped at a local shop since I donít have a lift and (at my age) itís too much to do laying on my back. Can I drive it home (15 miles) without any wiring in place? My next project is a complete rewire.

    Thanks

  8. #8
    Join Date
    Sep 1999
    Location
    Dbl Oak,TX
    Posts
    731
    My Feedback

    (0% Positive Feedback)
    Rep Power
    20
    The picture did not show up in the last post.

    It will be OK to drive without transmission wiring hooked up. The only caution would be if you have to floor it, the extra kick from a downshift won't be there.
    What has been, can be again. (Bob Wills, 1942)

  9. #9
    Join Date
    Jan 2019
    Location
    Victor, Ca
    Posts
    18
    My Feedback

    (0% Positive Feedback)
    Rep Power
    0
    I would say use a push button interrupter switch to provide 12v to the kickdown for on demand response, instead of a toggle.
    A separate toggle will do well for the Switch Pitch, I believe. I have a push button setup on my kickdown, and it works well for me.
    I currently don't have the Switch Pitch installed, similar scenario. I have two ST300's here, one with SP, one without.
    My SP tranny is in need of repairs, and I think that even if I did have it back to full operation; I would still keep the added little interrupter switch for fun.
    It's nice to be able to kickdown without going full throttle. She still gives a nice surge of power with just a bit more gas, instead of pedal to the floor.

Similar Threads

  1. St300
    By ericas67buick in forum Transmissions and Drivelines...
    Replies: 5
    Last Post: 03-04-2015, 01:49 PM
  2. Exchange ST400 for ST300 in '65 GS?
    By 5GScars in forum Transmissions and Drivelines...
    Replies: 4
    Last Post: 06-26-2008, 04:44 PM
  3. ST300
    By kidbuick in forum Transmissions and Drivelines...
    Replies: 0
    Last Post: 11-22-2002, 04:22 PM
  4. ST400
    By big_riv67 in forum Transmissions and Drivelines...
    Replies: 1
    Last Post: 03-28-2002, 08:27 AM
  5. Is the 65 ST400 the same length as the 64 ST400
    By Nailed in forum Transmissions and Drivelines...
    Replies: 3
    Last Post: 10-27-2001, 11:54 AM

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
TeamBuick.com Privacy Policy