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mystery ford 289

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i just bought a 289, the people didnt know what it came out of and im having a hard time figuring it out. the intake is stamped 289 4 C50E-9425B i also found a stamp that says 7D5Z i believe its the date? any help would be greatly appreciated
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Are you sure that's C5OE and not C6OE? I found a listing for an intake manifold with C6OE but not C5OE. Basically it's a 4 barrel intake manifold for a Mustang/Falcon.
 

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Discussion Starter · #4 ·
The 7D5Z means the engine was assembled April 5, 1967.
and the
Are you sure that's C5OE and not C6OE? I found a listing for an intake manifold with C6OE but not C5OE. Basically it's a 4 barrel intake manifold for a Mustang/Falcon.
intake manifold is definitely C50E, but the exhaust manifolds are C60E-9430-F and C60E-9431-F
 

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The casting numbers show the first year that part was made, but often the same part gets used for a few years. If they made a 2V intake casting in '65, and didn't change the casting (which would change the part number) for a few years, then you can see why a "C5__" part number might be original on a block that was cast in 1967. The block part number and casting date are on the lower passenger side rear part of the block, roughly where the starter overhangs it.
 

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The casting numbers show the first year that part was made, but often the same part gets used for a few years. If they made a 2V intake casting in '65, and didn't change the casting (which would change the part number) for a few years, then you can see why a "C5__" part number might be original on a block that was cast in 1967. The block part number and casting date are on the lower passenger side rear part of the block, roughly where the starter overhangs it.
You are quite right. C5OE means the part was engineered in 1965 (C5) and paid for by the Fairlane Group (O). Might have been used for 2-3 years before a revision was needed.

That does not mean it was installed in a Fairlane, it could have been in anything that had a 289 engine.
 

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There are many a 289 out there that started life as a 2V and at some point someone swapped on a 4V intake and carburetor. I'm "guilty" of this about 5x..... This is most likely the case. What you'll probably find, if you pull the heads, are dished pistons with 4 valve reliefs.....
 

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If you get under the car and take off the starter there should be a casting number on the block on the shelf next to the oil pan. As mentioned above, anyone could have changed the intake in the past so you may want to find out what year design the block is to start.
Here's my pic from years ago in my '67 that has ended up on various Ford forums:
 

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i just bought a 289, the people didnt know what it came out of and im having a hard time figuring it out. the intake is stamped 289 4 C50E-9425B i also found a stamp that says 7D5Z i believe its the date? any help would be greatly appreciated
pull the valve covers and look for the engine size cast into the head, it will be 289 or 302. there will also be a 2V or 4V cast in the valley of the head along with a date code.
 
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