70 Z28 Leaf Springs

Discussion in 'Original Drivetrain Topic' started by camaro gold z28, Nov 3, 2007.

  1. DANZ

    DANZ Veteran Member Lifetime Gold Member

    Feb 28, 2004
  2. norwood

    norwood Veteran Member

    Apr 6, 2007
    Bartlett, Il
    The funny thing to me on this is that 70 Trans Ams as well as ALL Trans Ams including the WS6 pkg used 4 leaf springs
  3. x77-69z28

    x77-69z28 Veteran Member

    Feb 5, 2010
    long island, new york
    Resurrecting this thread to see if there has been any progress in the replacement of rear 5 leaf springs for my 70 Z28 project. My originals look just like White81Z's 70 307 springs. Has anyone deciphered the numbers stamped on the original springs? Mine are stamped M3289. Still need to know who has the most original looking springs. Eaton is still out of the loop as they still say that the 70 Z should have 4 leaf springs.
  4. KEVS79

    KEVS79 Veteran Member

    Mar 3, 2008
  5. x77-69z28

    x77-69z28 Veteran Member

    Feb 5, 2010
    long island, new york
  6. COPO

    COPO Veteran Member Lifetime Gold Member

    Sep 15, 1999
    Ontario, Canada
    When you buy them new and have them installed, you'll need to take measurements then remove them and have them de-arched at a spring shop cause most sit too high out of the box.
  7. Dave Nelson

    Dave Nelson Veteran Member Gold Member

    Dec 19, 2003
    Vineland N.J USA
    This is what I had to do.
  8. CamarosRus

    CamarosRus Veteran Member

    "The 1970 Camaro Packet information dated February 1970 offered by Chevrolet’s Customer Service Center lists the 1970 Camaro rear leaf spring chart in the Chassis Section on page 6 under Rear Axle And Suspension. The Rear Spring Chart lists the 1st Design Spring as 481992 PK, however this is not the correct part number or two letter code used on the Assembly Line for the 1st design spring and the 2nd design 3992580 rear leaf spring is not listed
    in this chart

    As with the rest of the 1970 Camaro packet information and the 1970 Camaro AMA Specification Sheets both dated February 1970, these early publications have some early dated information that is either incomplete or incorrect, with various changes being made thru out the 1970 Camaro production year that was not added to those publications

    A monthly publication provided by Chevrolet’s Service Department, which was sent to Chevrolet Dealerships called The Chevrolet Service News dated July 1970 has listed on page 16 a 1970 Camaro Service Spring Revision Chart with the correct 2nd design 3992580 rear leaf spring listed for the 1970 Z28 Camaro"

    This is a reprint of a portion of M21RSZ28's post #11 in this thread............

    So according to the infamous
    M21RSZ28 the 481992 OE 70Z28 rear spring was not a correct assy line number
    so I'll assume that the service replacement
    480881 isnt good either
    The aftermarket (for the
    480881) SRI# is 21-345 which DAYTON Spring mfg and sells thru www.SDTruckSprings.com

    I will be contacting DAYTON & EATON to see if they have any original blueprint info on the ABOVE 2nd design 3992580 Spring

    Anybody reading this have any knowledge on the
    21-345....Need to find "Somebody" who has installed the 21-345
    to SEE/READ the results.................

    John Bloake reports that the 2nd design OE 3992580 is aftermarket SRI # 21-301
    so that gives me more questions to ask/answer
    Last edited: Mar 4, 2018

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