# 1969 GTO engine ID help!!!



## masterclassics (Sep 15, 2009)

Hi, I just picked up a 69 GTO. It has a 400 in it, but the numbers don't add up. On the back is the 9790071 casting (68-69 400ci). The code on the block is a YH (only 428ci seemed to have the YH). To make matters more confusing, the date code APPEARS to be H187. Which would make it a 67 block but none of those were cast with the 9790071 from what I can find. 

Any help out there on this one, I'd really appreciate it. Its a very solid California AC/PW/PB/PS car and I ordered PHS on it, but this engine details would be good to sort out. Thanks for any and all help!!! :confused


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## masterclassics (Sep 15, 2009)

also my build date code on the data plate says 12B111. I know 12B is December 2nd week but what is 111?


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## even steven (Feb 27, 2009)

i would check the 2-letter code on the front of the block again.sometimes wear and or dirt can confuse your eyes.9790071 is def.68 or 69 400.keep in mind production started the previous year,so the build date could be correct for a 68 motor,which could mean the motor was changed or maybe its a 68 with a 69 front valance and rear bumper.is the ignition in the dash or on the column?


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## masterclassics (Sep 15, 2009)

ignition is on the column, its a 69 and the vin/title match. It sure looks like YH, and I know for sure the rear code is 9790071. Here are the pics


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## even steven (Feb 27, 2009)

i just found a list of codes for 1969 400.those letters are probably xh which was a 350 hp motor.it says they used two codes for automatic 400 350 hp xh and ys


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## even steven (Feb 27, 2009)

just moving post up


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## 68greengoat (Sep 15, 2005)

That makes sense. The XH matches the 9790071 too. They were found in B-body cars. Bonneville, Gran prix etc..... Good job even steven.
On the data plate, it looks like it originally had a gold interior with a Antique Gold Metallic exterior and was assembled in Arlington. Still not sure on the 12B111 or 128111.


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## masterclassics (Sep 15, 2009)

Yeah Even Steven you are totally right, it must be an X. That makes sense now, thanks for your help! Still confused on the 12B111, but I know 12B so maybe 111 will be ram air III? I can wish, phs paid for today and on the way!


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## 05GTO (Oct 6, 2004)

masterclassics said:


> Yeah Even Steven you are totally right, it must be an X. That makes sense now, thanks for your help! Still confused on the 12B111, but I know 12B so maybe 111 will be ram air III? I can wish, phs paid for today and on the way!


111 may indicate the car was scheduled for the 1st shift on the 11th of december.

The date code on the back of the block is for August 67 and would be for the 68 model year. Check the water pump, if it has 8 bolts it will be a 68 and 11 bolts will be for 69.


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