Z28 Engine Stamp help

Discussion in 'Original Drivetrain Topic' started by 1970camaronut, Jul 12, 2011.

  1. 1970camaronut

    1970camaronut Veteran Member

    Jul 25, 2010
    Port St Lucie, FL
  2. 1970camaronut

    1970camaronut Veteran Member

    Jul 25, 2010
    Port St Lucie, FL
    Should there be a partial VIN on this pad? thanks It's a 1970 Z28.
  3. High Country Z

    High Country Z Veteran Member

    VIN Code Format
    The vin code format is stamped onto most engines. The format consists of divisional identification number, model year, assembly plant designation and vehicle serial or sequence number.
    In 68-69 model cars, the serial (VIN) number of the car the engine was installed in is stamped next to, or under the engine code ID.
    Starting in 1970, the serial number is stamped either above the oil filter, somewhere on the block pad (in front of the cylinder head), or on the transmission flange somewhere. Chevrolet issued technical service bulletins to indicate which engines were to recieve a vin stamp, so who knows what could have happend (or not happened).
  4. flowjoe

    flowjoe Moderator Staff Member Lifetime Gold Member

    Feb 7, 2006
    The VIN derivative that is stamped on engines is due to federal law - if it was omitted it was an oversight on the line (i.e. by mistake) and not because GM sent out a technical service bulletin.

    The VIN derivative is stamped on engines and transmissions - not either or.

    Starting in 1969 the VIN derivative stamping on the engine sometimes ends up by the oil filter - due to the relocation of the alternator directly above the passenger side pad stamping there became more difficult.

    1970camaronut: In general (and it is not a hard rule), in 1970 most Norwood built cars have the VIN derivative stamped by the oil filter and most LA built cars have the stamp on the passenger side pad. Check down by the oil filter...very hard to make out due to rough casting down there.
  5. High Country Z

    High Country Z Veteran Member

    It's a crapshoot I guess, mines a Norwood and the vin is on the pad.
  6. FlaJunkie

    FlaJunkie Veteran Member Lifetime Gold Member

    Mar 24, 2001
    Rockledge, Florida
    I think Norwood 70 Z's just have the engine number stamped on the front pad. Look by the oil filter and you should see a partial VIN. You may need to take a macro closeup picture with a digital camera to help you see it.

    This Norwood engine number isn't unique as far as I know. It has a plant stamp, a date manufactured and a three letter configuration code. I would think there could be several different 70 Z28's with the same engine number on the front pad, but differ in the VIN stamped on the oil filter.

    If the engine was decked in the future, the engine number would be gone but the VIN would remain intact.
  7. High Country Z

    High Country Z Veteran Member

    Not the case with mine, it's a '71 but I don't see where that would make a difference.
  8. twozs

    twozs Veteran Member

    Aug 5, 1999
    hopewell jct ny
    i guess by 73 they figured it out .. [​IMG]

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