74 Z28 exhaust manifolds

Discussion in '1974 Specific' started by Jeep43, Sep 30, 2016.

  1. Jeep43

    Jeep43 Veteran Member

    764
    1
    Mar 30, 1999
    Connecticut
    In doing some research I find that the 3986330 was used on the RH side of 74 Z28 L82's (this site and others) but also read some info that the 330 was used only on early 74 cars. What was used on late 74 Z28's?? I have an HEI/ST-10 car.

    Also is there any interchange differences between a 3986330 and a 3959562?? If I need a 330 but use a 562 to install headpipes will a 330 swap in later without fuss??
     
  2. bodymanbill

    bodymanbill Veteran Member

    664
    96
    Feb 1, 2007
    South Park Pa
    image.jpg I have a 562 on my 73 Z they were off a 74 Z, my original 330 was missing. I have the smog holes plugged but im pretty sure they are interchangeable
     
  3. bodymanbill

    bodymanbill Veteran Member

    664
    96
    Feb 1, 2007
    South Park Pa
    Sorry about the upside down pic, cant figure out how to flip it
     
  4. McCune

    McCune Veteran Member

    624
    56
    Aug 22, 2015
    st.george utah
    330s are very hard to find. The 562 has the heat shield provisions where the 330 does not.
    [​IMG]
     
  5. Jeep43

    Jeep43 Veteran Member

    764
    1
    Mar 30, 1999
    Connecticut
    Other than the heat stove provisions its not functionally different?

    What would have been correct for late 74 Z28's???
     
  6. zfool

    zfool Veteran Member

    485
    3
    May 19, 2014
    Rochester, MN
    1974 Z28, R.H. Exhaust manifold PN 3959562 (warranty replacement is 3986330 due to cracking issues). L.H. Exhaust manifold PN 3989041 These are on a late production car.
    [​IMG]
    [​IMG]

     
  7. zfool

    zfool Veteran Member

    485
    3
    May 19, 2014
    Rochester, MN
    I see more of the 562's than the 330's. Most 562's possibly ended life in the scrap pile so it doesn't make sense in that respect. any info from other sources would be great. Possibly a Canadian parts book would have more detailed info.


    3986330 replaced by 336709 4/75
    69-73
    302, 307, 327 & 350
    RH
    Camaro and Z-28 200, 210, 245, 250, 255, 290, 300, 330 & 360 HP 1.9" Outlet A.I.R.

    3959562 This one is tough to track down. unknown replacement date, prone to cracking and warranty work, 3973432 (This was a non Z28 in previous years) replaced by 336708 2/74 replaced by 3462222 6/75
    72-74
    307, 350 & 400
    RH
    Chevelle, Camaro and Z-28 115, 130, 145, 150, 160, 165, 170, 175, 180, 185 & 245 HP 2.0" Outlet A.I.R.

    3989041 replaced by 336710 12/74
    69-74
    302, 307, 327, 350 & 400
    LH
    Camaro, Z-28 and Nova 115, 130, 145, 150, 160, 165, 170, 180, 185, 200, 210, 245, 250, 255, 290, 300, 330 & 360 HP 2.0" Outlet with without A.I.R.
     
  8. Z28PILOT

    Z28PILOT Veteran Member Lifetime Gold Member

    2,015
    13
    Oct 8, 2009
    Emerald Isle , NC
    My car is a very very late Z28 with 562 and 041 manifolds with smog provisions . These are mostly what I seen on 74 Z cars . Just my 2 cents.
     
  9. CamaroNmotion

    CamaroNmotion Veteran Member

    243
    2
    Jan 8, 2006
    Buffalo, NY
    My 02B build has the 041 LH & 562 RH with smog provisions. So, Fred my Feb build has the same exh manifolds as your Aug build date.
     
  10. Jeep43

    Jeep43 Veteran Member

    764
    1
    Mar 30, 1999
    Connecticut
    Well that's too bad. My came with a nice used 336709 (with only the 2 & 8 runners drilled for smog) and what appears to be an NOS 336710.

    I have 2 pairs of 562/041's but they are rather crusty...

    Is there a common spot where they crack?
     

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