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  • 72 Small block exhaust manifolds
  • 72 Small block exhaust manifolds
  • 72 Small block exhaust manifolds
  • 72 Small block exhaust manifolds

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  1. #1
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    Default 72 Small block exhaust manifolds

    Early cars have a different exhaust manifold than late cars...what would be considered early?

  2. #2
    Member Vettehead Mikey's Avatar
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    Best look in an NCRS judging manual. Changeover from early to late config. parts can occur just about anywhere during a production year. Example- the 'early' grills on '73s continued till three weeks before the very end of the production year.

  3. #3
    Member paz72vette's Avatar
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    my 72 was the 6491th produced and is concidered an early production for the electrical. I have a timer for the seat belt light insead of a switch in the belts.


    Cheers

  4. #4
    Member 6880 Mike's Avatar
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    Early and late almost always pertain to specific running changes made on the assembly line. My NCRS Specifications Guide says 3932461 left and 3989036 right were used early on the base engine cars and are not tapped for AIR except on California cars. Later versions used the 3932461 on both sides. It does not list a date for this change.

    What is the time/build date for your car?


  5. #5
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    Quote Originally Posted by 6880 Mike View Post
    Early and late almost always pertain to specific running changes made on the assembly line. My NCRS Specifications Guide says 3932461 left and 3989036 right were used early on the base engine cars and are not tapped for AIR except on California cars. Later versions used the 3932461 on both sides. It does not list a date for this change.

    What is the time/build date for your car?

    Hi,
    October 14th is what the birthday book tells me.

  6. #6
    Member 6880 Mike's Avatar
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    October was the third month of production and, in a generic sense, could be considered early. I checked the AIM and the NCRS Judging Guide and neither mentions the change in manifolds.


  7. #7
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    Quote Originally Posted by 6880 Mike View Post
    October was the third month of production and, in a generic sense, could be considered early. I checked the AIM and the NCRS Judging Guide and neither mentions the change in manifolds.

    I also checked the same with no luck. Thanks for doing that, i appreciate it.!

  8. #8
    Member 6880 Mike's Avatar
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    Quote Originally Posted by spleech View Post
    I also checked the same with no luck. Thanks for doing that, i appreciate it.!
    I'd still like to know when the change occurred.

  9. #9
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    Quote Originally Posted by 6880 Mike View Post
    I'd still like to know when the change occurred.
    I'm going to contact NCRS to try and find out. I"ll let you know.

  10. #10
    Member Vettehead Mikey's Avatar
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    Another way of skinning the cat would be to look at castings dates on manifolds. If some can be found that are dated a few weeks or a month or more before the assembly date of the engine (not car) it's reasonable to think that this might be the introduction date for the later pieces.

    I went through such an issue trying to track down a correctly dated intake for my '73. All the manuals indicated that it should have had a 3997770 or 3997771 casting number, yet I could find none that were reasonably close to the engine assembly date of mid June '73. All I could find were 340261 which supposedly was not introduced until the '74 model year, yet had casting dates that seemed excessively 'early' to coincide with the model year change over. Long story short, it eventually came out that the 061 had been seen on some late production '73s and was a 'legitimate' part number.

  11. #11
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    Quote Originally Posted by Vettehead Mikey View Post
    Another way of skinning the cat would be to look at castings dates on manifolds. If some can be found that are dated a few weeks or a month or more before the assembly date of the engine (not car) it's reasonable to think that this might be the introduction date for the later pieces.

    I went through such an issue trying to track down a correctly dated intake for my '73. All the manuals indicated that it should have had a 3997770 or 3997771 casting number, yet I could find none that were reasonably close to the engine assembly date of mid June '73. All I could find were 340261 which supposedly was not introduced until the '74 model year, yet had casting dates that seemed excessively 'early' to coincide with the model year change over. Long story short, it eventually came out that the 061 had been seen on some late production '73s and was a 'legitimate' part number.
    I'm going to try and contact a C3 judge at NCRS and see what he says. Thanks for your input!

  12. #12
    Member Vettehead Mikey's Avatar
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    Default

    Many of the replies here have been from C3 NCRS judges

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