70 Z28 - Are these smog tubes any good

Discussion in 'Original Drivetrain Topic' started by COPO, Mar 9, 2010.

  1. COPO

    COPO Veteran Member Lifetime Gold Member

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    The smog tubes I bought from GM a few yrs ago are anadized but they only had 73-74 for the pass side, and the virtical piece is set back farther and is curved.
    Not sure if I want to put the 73-74 on cause of the curve.

    What are these like? Made in China? http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=370280122765&fromMakeTrack=true

    330508 - 2-4-6-8 cyls (73-74)
    343763 - 1-3-5-7 cyls (they flatten out between cyl 1-3) who are these dumb asses repoping incorrect specs? Doesn't GM check their work?

    Anyone in Canada replace theirs with new ones and still have their old ones they want to get rid of if they are usable?
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    Last edited: Mar 9, 2010
  2. ronzz572

    ronzz572 Veteran Member Lifetime Gold Member

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    Mark i used the ebay style on my car. They fit very well and have the closest original look. If you want a nice exact set of original looking smog tubes contact Bill Hodel at 330-832-0871. Not shure what he sells them for now days, But if you find out let me know.I may remove my repopped tubes for his and sell mine if your interested. Also you may want to install your smog system non functional, one good back fire from a faulty smog diverter valve can cost you a expensive exhaust system repair.
     
    Last edited: Mar 9, 2010
  3. ronzz572

    ronzz572 Veteran Member Lifetime Gold Member

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    Anyone know how to devane a smog pump make it non functional.
     
  4. Z28PILOT

    Z28PILOT Veteran Member Lifetime Gold Member

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    Yep .....I "had" one of those weird flatten ones on my car. I thought it looked bizarre myself.. I found a NOS recently for 60.00 ...thought that was decent price.
     
  5. Z28PILOT

    Z28PILOT Veteran Member Lifetime Gold Member

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    On my 454 Corvette, I just Pulled the housing apart 20 years ago, and bust the vanes or fan part out , so it spins free on just the bearing , little or no load on the engine.. I cut LEAD PLUGS and shovel inside the large hoses to stop them up . I disarm all that junk . My car even passed an emisson inspection before it retired from "EVER" having yearly inspections again....:crazy: ;)

    I 've been trying to sort out smog and TCS garbage on my Camaro.... what a stupid mess.:)
     
  6. Z28PILOT

    Z28PILOT Veteran Member Lifetime Gold Member

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    Weren't the GM injection pipes actually a GRAY/Phosphate ( near black ) ? LEAST the originals on my corvette were??
     
  7. COPO

    COPO Veteran Member Lifetime Gold Member

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    Not sure if you can tell but here's my old pipe showing an original tower clamp. When I removed the hose the valve end was still anadized.

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    Last edited: Mar 10, 2010
  8. Z28PILOT

    Z28PILOT Veteran Member Lifetime Gold Member

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    It also maybe a "YEAR" to year variation deal ,or supplier change to keep parts on the shelves for years and years. My corvette is late 74 production ....it has the near black tubes with gold check valves and the wide flattened brazed swedge of the large tube down to the small pipe. Actually . I have a pair of originals that were the gray /black off a 74 Nova ...... I was going to put them on my camaro ...TILL ..:screwup: I saw a hairline crack in one tube that does go all the way though . So........I found the NOS tube to replace it, and just wound up painting the gold opposite side tube with 1500 degree flat black, it is really close to the gray phoshate GM tube. So close that you have to hold them side by side to tell the diff.

    In the correct tube as COPO pointed out there is a BEND or curve. ..... the after market .......it appears they decided to CRUSH the tube instead of going to the trouble of a bend.:confused: If I had pics , or car near by I'd show them
     
  9. COPO

    COPO Veteran Member Lifetime Gold Member

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    Side by side shots I took for my web site of 70 Z28 pipes and new GM pipes. Remeber the passenger side I had to order 73-74 tubes cause the 70-72 were NLA. There is no reason for the flat area on the drivers side. WIERD. I'm not impressed what GM lets vendors get away with. Probably made overseas and you know where that is.

    Why isn't GM doing quality checks?

    Both new sets of pipes that screw into the exhaust manifold are of different lengths.
    The pass side cyl 4,6 are 1-7/8
    The divers side cyl 3,5 are 1-3/4
    The 70 original length is 1-5/16

    Why do people complicate things?


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    Last edited: Mar 29, 2010
  10. soonercrew

    soonercrew Veteran Member Gold Member

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    i would call jeff at (954) 791-1779... or his website is www.pacecarjeff.com
    he has alot of nos and original smog stuff (tubes, pumps, diverters...etc...), and he can probably find a date match too, if thats what your looking for...
     

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