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Discussion Starter · #1 ·
Knowing what we know about Ford engine date codes, a matching numbers 390 engine block to a car built on 11/10/66 would be a 6J or a 6K block. Even better would be a set of heads with 6J or 6K and a month date maybe a little before block date. Ie; 6K18 block with a matched set of heads dated 6K11. BUT... my question is..would there ever be a chance the head date code would perfectly MATCH the block date code? I feel the separate production of these components in a factory/plant would make this impossible..
 

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Out of the millions of cars produced, it probably happened on occasion by random accident, but I agree, it's probably very unlikely/unusual.
 

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Yes, possible. However, the majority of engines from that era have either been scrapped or rebuilt, so there is no "real" way of guaranteeing how many or if any could have come that way.

Also, for some items, they were not "made" everyday, but made in batches. For example, the steering gear box. If the production capability is 1000 units per day, and 500 Mustangs and 100 Falcons a day are being built, then Day 1 runs 1000 Mustang, and Day 2 might have 1000 Falcon units built. But since Falcon only is building 100 cars per day, then no more Falcon units will be built for another 10 days (simple illustration, not going into did all cars have the same gear box, etc.).

Easier to run a line in batches than in onsey twoseys
 

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Discussion Starter · #4 ·
Yes, possible. However, the majority of engines from that era have either been scrapped or rebuilt, so there is no "real" way of guaranteeing how many or if any could have come that way.

Also, for some items, they were not "made" everyday, but made in batches. For example, the steering gear box. If the production capability is 1000 units per day, and 500 Mustangs and 100 Falcons a day are being built, then Day 1 runs 1000 Mustang, and Day 2 might have 1000 Falcon units built. But since Falcon only is building 100 cars per day, then no more Falcon units will be built for another 10 days (simple illustration, not going into did all cars have the same gear box, etc.).

Easier to run a line in batches than in onsey twoseys
This is what I’m imagining in a big operational factory or plants. I was looking for heads to match a 6K18 block and found a matched set of 6K18 heads. Being an impossible find, I’m naturally excited... but, knowing this could be impossible from the factory kind of ruins the original build I was going for ..
 

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Discussion Starter · #5 ·
Out of the millions of cars produced, it probably happened on occasion by random accident, but I agree, it's probably very unlikely/unusual.
I was looking for heads to match a 6K18 block and found a matched set of 6K18 heads. Being an impossible find, I’m naturally excited... but, knowing this could be impossible from the factory kind of ruins the original build I was going for ..
 

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This is what I’m imagining in a big operational factory or plants. I was looking for heads to match a 6K18 block and found a matched set of 6K18 heads. Being an impossible find, I’m naturally excited... but, knowing this could be impossible from the factory kind of ruins the original build I was going for ..
Well, it's not "original" anyway so what are you trying to create? I think it would be kind of cool to have an exact match. After all, you can't (or shouldn't) present it as the original complete engine so what is the purpose?
 
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Discussion Starter · #7 ·
Well, it's not "original" anyway so what are you trying to create? I think it would be kind of cool to have an exact match. After all, you can't (or shouldn't) present it as the original complete engine so what is the purpose?
I am building a matching numbers motor 67 fastback. What I have for a block follows the guidelines for what would’ve been in the car from the factory. The amazing find on these heads are less likely to be on this block. But, I’m going with it anyway because it’s just too cool at this point that these parts were cast on the same day.
 

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Do we know Ford didn't cast blocks and heads on the same day in the DIF? Certainly, there was more than one shift per day. Would different shifts cast different parts?

What could be important too would be the engine's ID tag showing the assembly date. If heads, blocks, intakes, etc. were cast on the same date, then there's no reason they couldn't have been assembled together on a motor.
 

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Discussion Starter · #9 ·
Do we know Ford didn't cast blocks and heads on the same day in the DIF?

What could be important too would be the engine's ID tag showing the assembly date. If heads, blocks, intakes, etc. were cast on the same date, then there's no reason they couldn't have been assembled together on a motor.
This is my take on that: the date code shows the actual cast date. My heads and block were cast on the same date. But, block assembly and head assembly is assumed to be in two areas. When the heads are complete, I’m guessing they are placed in rows ready to be assembled to blocks. All engines in the finished autos have different dated heads than the blocks, but, usually close to, or have the same letter (month). I imagine they grabbed heads to assemble and many heads do have the same day together- but not matched to the block date. Someone on the assembly line would have to find the date on the block, then go through all the heads to find the match and grab those which no one would care to do when their full time job was assembling engines.
 

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Agreed.

Also, the answer to my question (assuming blocks and heads were cast at the same foundry [DIF]) is yes based on the parts you have. Of course they may have been machined on different dates, but no reason they couldn't have been put together on the assembled motor either.
 

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Discussion Starter · #11 ·
Agreed.

Also, the answer to my question (assuming blocks and heads were cast at the same foundry [DIF]) is yes based on the parts you have. Of course they may have been machined on different dates, but no reason they couldn't have been put together on the assembled motor either.
Yes. I wanted to get this question out to blogs because I’m hoping that there is some knowledge that it’s possible that workers might select matching dates on heads to blocks back then, but, I really doubt it. I’ve never seen a 390 with all matching dates yet..
 

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I would almost guarantee a motor assembly worker would never care about date matching heads to a block. They were interested in building a motor as fast as they could with the parts available coming off the line. It would be pure coincidence.
 
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Steve, I have not worked for Ford, or any other car manufacturer, but I HAVE worked on a large assembly line. There were about 20 of us on the section where I was. Everyone had a button to stop the whole line. If someone DID stop the line, there is a light that comes on in the foreman's office so EVERYONE will know very quickly WHO stopped the line ! G-d help you if its you. You use what ever is within reach to keep that line going. There is NO TIME to look at dates. Doesn't happen now, and back then, the line speed was even faster. LSG
 

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Is it possible, yes. Is it likely, no. Here is an aerial view of the plant in 75. Iron ore goes in one side, complete motors come out the other. I have had several motors with one or two day differences in date codes and one that had the heads and intake the same. I remember that one in particular because I thought that was pretty remarkable at the time.

798234
 
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