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Discussion Starter #1
Hello all. Very new to the forum never posted but have been lurking for quite some time. About 2 months ago I bought a 1969 GTO from an auction. They claimed it to be all original and body wise everything appears to be there. The Engine on the other hand after a little investigation I am having my doubts on. I haven't had a chance to get all of the numbers off of it yet as it is not being stored anywhere near where I live at this time. What I did get off it for sure was a XH on the engine block. I have done some research and from what i can find XH engine blocks were only used on B-body cars. However the date stamp F159 tells me it is period correct. So I guess in a nutshell my question is did they ever put the XH engine block originally into a GTO from the factory? Or did someone put this engine in at a later date with a period correct engine? I have not had a chance to PHS document it yet but plan to in the near future. Thanks in advance guys.

PS. Sorry about the crappy pic but it's all i have for now.
 

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Discussion Starter #3
Not sure of the heads. My apologies i havent gotten around to getting all numbers off of it yet. Is there a specific head i should be looking for? Also, what is the significance of the head numbers?
 

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The combination of head casting number (usually on top of the center exhaust ports, a few were on the 'front' (or rear) port) and the head date code (same format as the block date code) will ID which heads it has. Heads differed in valve opening sizes, rocker stud type (screwed in or pressed in) and in some cases, exhaust port configuration.

That block date (June 15, 1969) is very close to the point where the engine foundry would have been switching over to start making engines for the 1970 model year. (See if you can find a large '70' on the top rear of the block nearby the block date code.) In 1970, XH still indicated a Grand Prix with an automatic transmission, same as 69.

On the front of the block, passenger side, down low next to the timing cover, and running vertically, there should be a partial VIN. A "2" followed by the last 8 characters of the VIN number from the car that was built with the engine originally.

Bear
 
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