# Engine identification



## pjk (Jan 10, 2014)

Looking for some help in identifying the engine in my newly purchased 67 GTO. The numbers on the block are 278436 with a YS right underneath them. I do believe this is a YS code engine with 335 horsepower. But how do I know if it is original to the car and if not what year would the engine be? Thanks in advance for any help given.


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## BearGFR (Aug 25, 2008)

Google up "Pontiac engine codes" and you should get several hits with reference information, including photos/diagrams. You'll want to start with the date code near the distributor to figure out what year the engine is, then use the casting code (low, down behind the passenger side head), and finally the YS. "YS" and the other codes like it were used in multiple years and sometimes meant different things depending on the year. That's why you always begin with the date code.

Bear


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## pjk (Jan 10, 2014)

Thanks for the help Bear, I will look for those numbers.


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