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Transmission identity

Discussion in 'Chevy Trucks' started by TRUP, Feb 4, 2003.

  1. TRUP

    TRUP Member
    Messages: 38

    I thought the transmission for an 82 K20 was supposed to be a "400", but looking at the shape of the oil pan, indicates that I might have a swap. The transmission oil pan on my K20 is square, and I have seen diagrams of the oil pans of 400's, and they're anything but square. Doesanybody care to take guess at what kind of tranny I have? The tranny runs okay. I'd like to know what it is, so I will buy the correct filter for it.:confused:
  2. paul soccodato

    paul soccodato Senior Member
    Messages: 430

    sounds like a th-350,
    is the pan is square with one corner cut off?
  3. John DiMartino

    John DiMartino PlowSite.com Veteran
    Messages: 2,154

    Sqaure pan,must be an early 700r4 trans.It is an OD trans,so you should have an oD on the shift selector,unless it was swapped in.Go under and look on the rear of the trans,the 700R4 does not use a vacuum modulator,the Th350/400 do.If it has one,its not a 700R4.
  4. TRUP

    TRUP Member
    Messages: 38

    No OD on the shift indicator, but "automatic overdrive" is printed on the indicator bezel. I thought the tranny was a 700 too.
  5. MTCK

    MTCK Senior Member
    Messages: 346

    Automatic Overdrive = 700r4 Shift indicator probably reads:


    With automatic overdrive printed underneath. Change that filter :)