Distributor Part #s and Specs, 1965, 66, 66, 67, 68, 69, 70, 71, 72, 74

Discussion in 'Buick FAQ' started by LARRY70GS, Jan 19, 2018.

  1. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD"

    Ethan (Hugger) asked me about this so I thought it would be useful to post. It is in order top to bottom starting with 1965. I am missing 1973, anybody have that? Post it.

    1965IgnitionSpecs.jpg 1966IgnitionSpecs.JPG 1967IgnitionSpecs.JPG 1968IgnitionSpecs.jpg 1969DistSpecs.jpg 1970IgnSpecs.jpg
    1971IgnitionSpecs.JPG 1972IgnitionSpecs.jpg 1973DistributorSpecs.jpg
    1974BuickIgnitionSpecs.jpg
     
    Last edited: Jul 30, 2018
  2. Bigpig455

    Bigpig455 Fastest of the slow....

    For what it's worth, here's 73. Had to take a pic of both pages cause dist info is split between both.
    upload_2018-7-30_5-13-2.jpeg
     

    Attached Files:

  3. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD"

    Thanks Rhett. I used Irfanview to clip out the pertinent information and create one image. I placed it in order in the original post. Best I could do with the low resolution shot. If you have a better picture of it, send that one to my E mail (in my signature), and I'll try to create a better image. For the time, it is legible. Thanks again.
     
    Last edited: Jul 30, 2018
  4. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD"

    1975 Ignition Specs.

    1975IgnitionSpecs.jpg
     
  5. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD"

    Some more distributor numbers and applications.

    DistributorListA.jpg DistributorListB.jpg
     
  6. 12lives

    12lives Engage! - Jean-Luc Picard

    Thanks Larry!
     
  7. RoseBud68

    RoseBud68 Well-Known Member

    Larry, I know have said it time and time again that these 455 like between 30-34* of total timing. As I see the chart for the '71 455 its states 16-20* of total timing.
     
  8. 12lives

    12lives Engage! - Jean-Luc Picard

    Manny - You have to add the max vac advance to the max centrifugal to get total.
     
  9. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD"

    That is correct, 71-74 distributors were like that as well. Must have been for emissions reasons because it really hamstrings the engines. Look at the Stage 1 distributors in 1971 and 72. 10* of initial + 20-24* of mechanical advance, 30-34* The 71-2 Stage1 cars would have been night and day power wise compared to the GS455, all because of the missing 12-14* of spark advance. Maybe Buick did that so the Stage1 engines would shine all the brighter?

    Yes, but vacuum advance drops out at WOT, leaving you with a maximum spark advance of 20* or so.
     
  10. RoseBud68

    RoseBud68 Well-Known Member

    Ahhh, I see now. Thanks Larry. At the moment I'm at 30* @ 2,000 RPM.
     
  11. 12lives

    12lives Engage! - Jean-Luc Picard

    And here I was thinking about cruising speed...I need to re-read your tuning thread Larry!
     
  12. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD"

    Correct, at cruising speed, there is a light load on the engine, and vacuum is high, so the vacuum advance supplements the partial mechanical advance, but at wide open throttle, vacuum drops to zero, and vacuum advance disappears. That leaves you with the sum of your initial advance and the mechanical advance that is in. With stock springs,full mechanical advance can come in as late as 4600 RPM. Cruising RPM is usually about 2000-2600 RPM, so only part of the mechanical advance is in, vacuum advance supplements that. That is why when you bring your mechanical advance in earlier, you need to limit the vacuum advance degrees to keep from over advancing.
     

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