# Help with decoding .



## Jrock (Jan 12, 2020)

I have a 1967 GTO that I bought from original owner . The previous owner said it is a 389, but I’m starting to question that . I also want to confirm that it is #’s matching. I have a lot of #’s and don’t know what they mean. Here we go.......
-Next to distributor: raised numbers 86133 under that is C137 and also there’s a D and a 8 .
( I know the C137 means March 13, 1967 )

the front of the block there’s a stamp that reads : 447398 with YS under it .
there isn’t a number stamped next to timing cover
and it has 3 freeze plugs .
Any suggestions or advice would be greatly appreciated ? Thanks guys


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## Jerry H. (Mar 19, 2020)

447398 is the engine production number. It will NOT match your VIN. It will match the engine # on PHS paperwork for 67. And it would match your warranty plate (protect o plate). YS is the code for a 335 hp, 400ci engine with automatic trans for a GTO.


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## O52 (Jan 27, 2019)

When was the car's build date? Should be three digits on the Fisher Body Plate on the firewall. If the engine is original the code should be within 6 weeks of the engine casting date C137. I'm guessing around April so the code would look something like this (04 A) 04 is the month, A-B-C-D or E would be the week. If built at the Pontiac plant it could well be 03 C or D.
A build date before the engine casting date would obviously mean its not original.


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## Jrock (Jan 12, 2020)

O52 said:


> When was the car's build date? Should be three digits on the Fisher Body Plate on the firewall. If the engine is original the code should be within 6 weeks of the engine casting date C137. I'm guessing around April so the code would look something like this (04 A) 04 is the month, A-B-C-D or E would be the week. If built at the Pontiac plant it could well be 03 C or D.
> A build date before the engine casting date would obviously mean its not original.


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## Jrock (Jan 12, 2020)

04C


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## O52 (Jan 27, 2019)

Although not proof positive of an original engine, its looking good.
PHS documents will confirm


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