# Where to find engine numbers?



## Artemis Entreri (Jan 13, 2010)

So my goats Trans and Engine are not the stock stuff, I know that for sure, my father had 4 gtos and a lemans at one point and switched engines/transmissions around depending which car was in better shape and which engine ran and whatnot.

So the question is a general one, where can I find where on the engine the numbers on, that will let me know what its from?

I'm 99% sure its a 389 from a GTO, which is what should of been in the 66 to begin with. The trans is a 4 speed manual, believe there was a 3speed in it when my pops got it.

So the engine and trans, where are the numbers so I can find out what they are exactly, and make sure they are something out of a GTO for sure.

Thanks all, :cheers
-Steve-


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## 68greengoat (Sep 15, 2005)

This should give you an idea where to look for codes.....

Pontiac Engine Codes


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## Koppster (Jul 27, 2008)

:agree 

....and here's another link with pretty much the same information in a searchable format

Pontiac Power


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## Pontiachris (Oct 30, 2009)

look on the block near where a bellhousing would bolt to near the distributor and if your block is 70 or newer it should have the displacement stamped on the drivers side near the freeze out plug towards the front of the motor


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## Artemis Entreri (Jan 13, 2010)

Thanks guys, I found the numbers 640106 on the block with YC under it, cant seem to find those numbers or what they mean, anyone have any ideas?


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## 05GTO (Oct 6, 2004)

640106 is the engine unit number which is similar to a serial number, the letter code YC was used for several years on b-body cars with a 2 bbl. The casting number you need is located on the distributor pad with the date code prior to mid year 1967 and then was moved to the rear of the block behind the #8 cylinder.

The block casting number for 65 and 66 (389) is 9778789 and 67 (400) is 9786133.


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