BBB vs SBB 4 speed parts

Discussion in 'U-shift em' started by 69SkylarkGS, Aug 29, 2019.

  1. 69SkylarkGS

    69SkylarkGS Well-Known Member

    My 69 GS is an original 4 speed car. The previous owner swapped a Chevy 350 in and I’m planning on putting a low mileage 70 455 in. I plan on reusing as much of the original 4 speed parts currently on the car as possible but would like to make sure I pick up all the needed BBB specific 4 speed parts.

    So far I’ve got a z bar on the way that I just bought. What else do I need that is specific to BBB? Any companies selling repops?

    I’ve got a Bellhousing/cover coming, will be buying a flywheel and clutch set up in the future.
  2. Clarkie

    Clarkie Well-Known Member

    The clutch fork is also BBB specific. I don't think think it is being reproduced, but I'm not 100% sure of it.
  3. 69SkylarkGS

    69SkylarkGS Well-Known Member

    Thanks for your response, seems that’s going to be nearly impossible, if it’s not reproduced, to find judging by my research. I’m wondering if the SB set up can be adjusted to work? I know a lot of people have done the 4 speed swap so I’m sure there is a trick if these parts are not available.
    knucklebusted likes this.
  4. knucklebusted

    knucklebusted Well-Known Member

    I have a SBB GS 4 speed that I'm thinking of putting my spare BBB in. I'm looking for any show stoppers like this. Eagerly following.
  5. buick64203

    buick64203 Just plum crazy Staff Member

    You can use the small block/ 442 style fork on a big block car. It doesnt have to be the clevis pin style.
  6. 69SkylarkGS

    69SkylarkGS Well-Known Member

    Ok great! If you do that is there a specific combination of parts needed for it to work? Meaning do I just use the small black parts with the small block ZBar or do I need to mix and match anything else such as use the big block ZBar?
  7. buick64203

    buick64203 Just plum crazy Staff Member

    Ok, the upper clutch rods are different between SBB and BBB. The big block is about 3/4" longer and has a bend in it that the SBB doesnt have. The bend is needed so the rod is centered in the hole through the firewall. The attachment point on the Z bar is taller than the SBB version. If you use the SBB upper rod with a BBB z bar, it rubs on the top of the hole in the floor plate. Pretty sure the Parts Place started repro-ing the correct upper big block clutch rod. Clear as mud?

    As far as floor plates, you can buy either a used one or a repro. In my case, I just used a hole saw and cut a hole in my automatic one.
    69SkylarkGS likes this.
  8. bignastyGS

    bignastyGS Maggot pilot

    I had a 350 4 speed setup in my 72 GS car behind my 462 motor.Ran 11.90's and never had any issues..
    69SkylarkGS likes this.
  9. 69SkylarkGS

    69SkylarkGS Well-Known Member

    Thanks a lot!!!! That definitely clears things up for me. This is my first 4 speed car and Buick so I’m a newb who is learning. I want to make sure I have all the needed parts when I do the 455 swap, that way I’m not stuck waiting on parts mid swap! I can’t wait to row some gears behind a BBB.

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