1974 Z Air Box Lids

Discussion in '1974 Specific' started by zfool, Aug 27, 2017.

  1. zfool

    zfool Veteran Member

    485
    3
    May 19, 2014
    Rochester, MN
    I've seen 2 different styles, one with dimples for the wing nut one without. I remember someone saying that the non-dimpled was a repop. I'm really questioning that after looking at the 2 personally. They are virtually identical with the exception of the dimples. Size, ridges, stamp marks, gasket and finish. One thing I've noticed that more with the HEI seem to be without dimples but not all. Possibly coincidence. Thoughts and Experience?

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  2. Twisted_Metal

    Twisted_Metal Moderator Staff Member Lifetime Gold Member

    25,270
    286
    Feb 26, 2004
    Bloomington, MN
    They are pretty close but obviously came from separate stamping dies.
    If it's an HEI related difference... You need to see the original bases with them as the HEI base will have an indent to clear the larger distributor.

    Personally... I have no knowledge of the different lids.
    They may have come from different suppliers when the change was made to HEI.

    I would think they would have been matched equally (bases and lids) and created by the same supplier. But that may not have been the situation as supplies ran out for certain parts and contracts with different suppliers were negotiated.

    Were the Z28 and other 4-barrel air cleaner lids different in any way that would have separated them from manufacture to assembly?
    Different stickers?

    Were over the counter GM replacement parts slightly different from originals?
    I've seen that situation with numerous parts. (Superseded parts, different numbers, different supplier with different dies, no date stamp etc.)

    Interesting mystery....
    Good luck in finding the truth!
     
  3. zfool

    zfool Veteran Member

    485
    3
    May 19, 2014
    Rochester, MN
    That's a good point on the regular lids, its seems like there is one that's close in shape. I have also seen a NOS OTC HEI box that had a black lid. There was another HEI box in California that I missed on Craigslist 3-4 years ago that had a black lid that the guy said he pulled off the car a few years after he got it new. So the Black lid is a possible player.
     

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