Topic: Casting dates on 289 heads

[Cool Times]

Good evening

Most of you guys are tired of answering date code questions, but I'm documenting all my part dates and sheet metal dates.  I have a 1967 A code fastback built in San Jose with a thermactor emission system.  My build date was May 8, 1967 and my 279 was cast on April 25 and assembled on April 27.  So, I always felt comfortable that the engine was original.  However, the other day, I pulled the valve covers to document the casting numbers on the heads. They both had 289 casts along with WF which I believe means Windsor Foundry.  However, to my disappointment, the heads were dated Jan 31 and Feb 2, 1967 which I believe suggests a matching set being only two days a part.  But, the heads and block casting dates are 80 plus days apart.  I'm concluding that they were swapped at some point - even though the engine was severely caked in grease before getting rebuilt.  Is my swapped conclusion correct?

Thank you
Mike

[Cool Times]

289 not 279

[J_Speegle]

..................... But, the heads and block casting dates are 80 plus days apart.  I'm concluding that they were swapped at some point - even though the engine was severely caked in grease before getting rebuilt.  Is my swapped conclusion correct?

So just to confirm the heads you currently have are Thermactor heads?   It was common to swap these out for non-Thermactor for some since the addition "bump" int he port was seen as a restriction by many for increased performance usage

Looking at the limited number of dates I have comparing head and engine block casting dates I would suggest that yes 80 days between the two is unusual and I don't have another example that is similar during 67  production

I can offer that I do have examples (other years) that are greater than the 80 days 9E15 compared to 9B21 and 9B28 which could just be another example of head swapping but we can't be sure. It is one heck of a coincidence that it they were swapped the owner/shop found out of all the tens (or more) thousands of heads they could have picked they choose another set of 69 heads and ones cast before the block. Especially since (if this were done) they were likely not even thinking about casting dates just finding usable heads.

In the vast majority of the examples I have records of the casting dates are most often the same month or two neighboring months

[Cool Times]

Thank you Jeff.  That is what I feared.  The heads are thermactor heads with one port for the smog valve.
Mike

[Cool Times]

Jeff,
Another question on date difference from build date.  My 1967 289 San Jose built A code was built on May 8 and I've found the casting part number on the third member of 6C0W-4025-A.  0n the pinion casting there's a few letters that basically illegible.  However has cast date of 6M9.  The 9 is hard to read, but it's clear to have been cast during Dec '66.  Is 4-5 months too far of a spread for a differential?

[Cool Times]

Forgot to say "Thank You"
Mike

[J_Speegle]

Jeff,
Another question on date difference from build date.  My 1967 289 San Jose built A code was built on May 8 and I've found the casting part number on the third member of 6C0W-4025-A.  0n the pinion casting there's a few letters that basically illegible.  However has cast date of 6M9.  The 9 is hard to read, but it's clear to have been cast during Dec '66.  Is 4-5 months too far of a spread for a differential?

Well the pinion retainer is only about a month which is fairly typical (one to two months is often found)  But have a few examples from 67 where 4 month spread was found between the rearend 3rd member casting date and the real completion date of the car

You didn't mention what you found on the third member

[Cool Times]

Jeff.  Not sure where to look.  Attaching two photos one of the third member and poorer image of the retainer.
Thank you for responding.
Mike

[Cool Times]

Second photo of retainer

Thanks
Mike

[J_Speegle]

Jeff.  Not sure where to look.  Attaching two photos one of the third member and poorer image of the retainer.
Thank you for responding.
Mike

Unfortunately (if the car is together) the date is on the inside surface (in the rearend housing) of the 3rd member by the passenger side bearing retainer

[Cool Times]

Thanks Jeff.  When I rebuild the third member, I'll find it and photo document.
Mike

[Cool Times]

Jeff

I was talking to a person who's business revolves around rebuilding certain classic mustang drivetrain components and he advised that my 289 with a cast dat of 4/25 and assembly date of 4/27 was too close to my build date of 5/8/67 build date on my 1967 mustang.  Thought it would be too short of period based on ship times to the San Jose plant.

Your thoughts?
Mike

[midlife]

Is your build date from the door VIN tag or from a Marti Report?  The VIN only shows the scheduled build date, not the actual date, which could be days to weeks later. 

[J_Speegle]

Is your build date from the door VIN tag or from a Marti Report?  The VIN only shows the scheduled build date, not the actual date, which could be days to weeks later.

+1  Great question to confirm the facts and the basis to work from

[Cool Times]

Hello

Scheduled date was May 5 and per the Marti report, the actual date was May 8.

Thank you
Mike