# 68 GTO Intake Manifold date code question



## trevorhoare (Jul 31, 2010)

Can anyone tell me how far in advance an intake manifold might have been cast as compared to the car it was put into.
I purchased an intake manifold #9790140 for my 68 GTO, but it is dated G117 (the G is hard to read, might be something else). 
I have decoded this as July 11 1967 (is that correct). 
Just curious if anyone could tell me when the actual car that manifold went into was likely made.
Also, it came with the original 5 port thermal vacuum switch which I've been having a hell of a time trying to find.

Thanks!
Trev


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## lars (Sep 28, 2004)

G117 is July 1967 - your interpretation is correct. Cast parts were often cast up to 6 months in advance of being installed on the engine/car, but it's not unusual for parts to be only weeks ahead in the date as well - inventory control was not a big deal in '67. Anywhere from 2 weeks to 6 months is a "good" casting date.

If you're concerned about whether or not the manifold is actually a '68 versus '67 manifold, the two are completely different: The '67 Q-Jet manifold has the "smiley-face" exhaust heat crossover groove that runs in an erratic, "smiley" shape just forward of the 2 primary throttle bores. If you have the "smiley-face," you have a '67 manifold. If the carb mounting surface is solid and flat forward of the primary bores, you have a '68 manifold.

Lars


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## trevorhoare (Jul 31, 2010)

Thank you!. It's definitely a 68 manifold. I imagine it must be for one made early in production with a date code like that though. 

What would I compare it to on my GTO to determine if it was "good" for my car? I'm guessing the build month on my data plate under the hood.









That says 05E so.. the 4th week of May? I'm guessing that's too far away to be considered the "correct" manifold.


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## lars (Sep 28, 2004)

Your comments and evaluation are correct. You have an early-production manifold, and a late-production car. It's highly unlikely for that manifold to have ended up on that car based on the dates, and most people would probably raise the BS-flag if you claimed it to be original and correct. But it's not impossible, and I've see stranger things happen on the assembly line cars: It would be "impossible" if the manifold date was later than the chassis build date code, so you have that "plausible" thing going for you... :cheers


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## trevorhoare (Jul 31, 2010)

Well, I suppose I'm better off selling this one and hoping to find one with a closer date code. The main reason I got it was because it came with the thermal switch which seems to be impossible to find, so at least I've got that.
I really appreciate all the help!
Trev


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## bsuburban (Jan 26, 2018)

If you still have this G 11 7 manifold I would like to buy it


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## bsuburban (Jan 26, 2018)

hello,
If you still have this G 11 7 manifold I would like to buy it


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## Pinion head (Jan 3, 2015)

G117 may be the earliest production date casting (non Developmental) of a '68 intake. 

How early is your '68? I've had numerous early '68 4bbl intakes cast in Hxx7 (August), currently the earliest have in stock is a J207.


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## bsuburban (Jan 26, 2018)

engine G 11 7
Heads F 27 7
Car sept 1967
vin is on the block


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## Grant from Nova Scotia (Jul 12, 2021)

Pinion head said:


> G117 may be the earliest production date casting (non Developmental) of a '68 intake.
> 
> How early is your '68? I've had numerous early '68 4bbl intakes cast in Hxx7 (August), currently the earliest have in stock is a J207.


Hi there. Any 9790140 manifolds available?


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## O52 (Jan 27, 2019)

They're out there. Seen a few on Ebay lately and the PY forums. Pontiac made two different 4 bbl manifolds for 68. The correct one would depend on when your engine / car was built. What date is on your Fisher Body Plate and / or engine block casting date?


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