What would be cosidered a "Date Correct" block

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My Car
1971 Mustang Mach 1, M code, 4 speed.
In the past, I've posted about my '71 351C 4V that has cylinder and piston damage due to incorrect timing. My car is "Date Correct" (or number matching if you want to go the GM way). What I need is input on what date codes would be considered correct for a replacement block should I need to take that route. Some have told me that the MCA accepts date codes as much as 6 months prior to the build date of the car. My original block is 1A7 (1971 Jan 07) and built on Feb 12th. The car's build date is 1B22. I have 2 blocks available. One is 1A26 and the other is 0K28. Both are D0AE-L blocks. I'm guessing the 1A26 would be closest, but what I don't know is how long Ford aged their blocks before use at the Cleveland plant. My point is it might be a bit too new for the build date. No one seems to know much about Ford's production policies. Did they just use what was available at the time, or was there an aging requirement before Cleveland blocks were used. I recently talked to a guy who worked at the Windsor engine foundry back in the early 70's and Windsor blocks were aged up to 8 weeks prior to being machined. From this, it would seem that Cleveland did not age as long as my original block is only just over a month from casting to build date.

Anyone care to comment on this? I guess the good thing about the early Cleveland's is, in my case anyway, there is no VIN or other identifying number stamped on the block.

Geoff.

 
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Geoff,

The VIN may be hard to see but was stamped into the block. It is located just below the rear of the drivers side head. Here is an example pic of what it looks like.

be8o6s.jpg


 
Geoff,

The VIN may be hard to see but was stamped into the block. It is located just below the rear of the drivers side head. Here is an example pic of what it looks like.

be8o6s.jpg
That's interesting. When I removed the engine in 2012 for the first rebuild, I looked very carefully at the block for numbers so I could be sure I got back MY block and not a switch. There was nothing anywhere, so I added a secret mark. The VIN was stamped on the top of the gearbox flange. Transmissions and engines were put in as a unit, so I'm guessing that as long as it was on one or the other, the guy on the line didn't care as long as he put it in the right car.

I'll recheck later as the engine is at the shop, but I'm sure there is no VIN on my block, nor is there one on the spare blocks I have. I think Ford changed to adding the VIN later in the 71 year, but I could be wrong.

 
Jeff is correct - your block should have the VIN

Ford used VIN stamping on engines and transmissions before 1971

 
[attachment=36678]

Jeff is correct - your block should have the VIN

Ford used VIN stamping on engines and transmissions before 1971
Thanks guys for you replies. Now I do feel like the village idiot!! I rechecked my spare 1A26 block and I did find very faint numbers that actually do not look like a sequential VIN. It appears to read 1F561694. The first two stamps are almost unreadable, but the latter can be made out reasonably well. I guess I need to go to the shop and take a much closer look at my block as that is the only way to be really sure. I'm having some trouble uploading the picture, site keeps dropping.

Wow success!!

 
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The 0K block is a bit long in the tooth for your car, but the 1A26 is fine. Won't be numbers matching, due to the VIN.

There was no "aging" of the block. They were manufactured at the Cleveland plant and shipped to Dearborn, often times sitting for a few weeks as inventory was used up.

 
.

block dates are typically between 10 days and 6 weeks before the actually build date of your car . . for the MCA to say that blocks that are dated 6 months before the build date are acceptable for concours is not only ding a disservice to people that actually have the orig block in their car, it is also laughable . . if your car does not have the orig engine, the date code is irrelevant to any intelligent buyer . . "almost" original is not worth anything close to original.

 
1F562864 appears to be about the last Cougar made at Dearborn in 1971. And I'm thinking they ran production into August. So, I'd think your new block "1F561694" was for Summer production.

 
The 0K block is a bit long in the tooth for your car, but the 1A26 is fine. Won't be numbers matching, due to the VIN.

There was no "aging" of the block. They were manufactured at the Cleveland plant and shipped to Dearborn, often times sitting for a few weeks as inventory was used up.
Thanks Midlife for that info. Much as I thought on the 0-K block, but it is an alternative. As for the cast aging, that too is what I needed to learn and what I figured it to be.

Geoff.



.

block dates are typically between 10 days and 6 weeks before the actually build date of your car . . for the MCA to say that blocks that are dated 6 months before the build date are acceptable for concours is not only ding a disservice to people that actually have the orig block in their car, it is also laughable . . if your car does not have the orig engine, the date code is irrelevant to any intelligent buyer . . "almost" original is not worth anything close to original.
Thank you too barnett468, This is the info I needed and yes, I agree, almost is not the same, but close may have to be good enough. As said before, this is all for a back-up plan should MY block be not usable without sleeving it and that is something I really don't want to do......yet.

As for the MCA part, it is amusing how much miss-information there is out there. I was told that by a friend who is restoring a 70 Boss 302 to original spec. Hmmmm!



1F562864 appears to be about the last Cougar made at Dearborn in 1971. And I'm thinking they ran production into August. So, I'd think your new block "1F561694" was for Summer production.
A Cougar block eh!! I have no idea what this block was in, but it fits with your set of numbers. I'm learning new stuff every day, so thanks to all.

Geoff.

 
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My 72 Mach 1 was built in August 71, the block has the last 6 digits Vin # stamped on the drivers side back of the block under the head. As far as date codes on the engine go 1 cylinder head was cast in May of 71 the other June of 71 and the block was cast on June 28 of 71 with actual engine assembly taking place on August 19,1971.

 
My 72 Mach 1 was built in August 71, the block has the last 6 digits Vin # stamped on the drivers side back of the block under the head. As far as date codes on the engine go 1 cylinder head was cast in May of 71 the other June of 71 and the block was cast on June 28 of 71 with actual engine assembly taking place on August 19,1971.
Ron, thanks. It is now obvious that blocks did have VIN's stamped on them despite what some websites will indicate. I was under the impression that it was not until the middle of 71(Q codes) that VIN's were used on blocks. Goes clearly to show that you can't always believe what you read or hear.

As explained earlier, I may have to replace my block and was needing info on what would be an appropriate date code so I could at least keep it close to correct. It now is obvious that I will have to rebuild the original engine no matter what the cost. As that engine has not yet been stripped, it may not be as bad as I'm thinking. I guess I'll have to wait and see, soon I hope.

Thanks to all, I now have very valuable information, which in turn will help others. I'll be sure to post the outcome in the coming months.

Geoff.

 
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Geoff,

Just one more piece of info for you if you were not aware...the transmissions were also stamped with the VIN on the top. You can not see it while it is installed but here is a pic.

29bdqat.jpg


 
How many cylinders are damaged? If it is only a few it might be worth sleeving the damaged cylinders. Just a thought. Chuck

 
.

block dates are typically between 10 days and 6 weeks before the actually build date of your car . . for the MCA to say that blocks that are dated 6 months before the build date are acceptable for concours is not only ding a disservice to people that actually have the orig block in their car, it is also laughable . . if your car does not have the orig engine, the date code is irrelevant to any intelligent buyer . . "almost" original is not worth anything close to original.
I agree that numbers matching brings the best value for restored cars. The next best thing is to get a period correct replacement and that usually means a date code prior to the cars assembly date. I have been doing a lot of research on my RR project and found that Plymouth produced the engine blocks up to 6 months before the cars production. Others parts such as intake manifolds, distributors, these usually have date code of up to 6 weeks from production. So I believe that MCA using 6 months is not out of line for being acceptable for concours. The Vin stamp will ultimately identify it as numbers matching no matter what the casting date is as long as it is before the assembly line production date. These of course are just my personal opinions and what I have found while researching my new project.

 
Geoff,

Just one more piece of info for you if you were not aware...the transmissions were also stamped with the VIN on the top. You can not see it while it is installed but here is a pic.

29bdqat.jpg
Jeff, yes I knew the trans has the vin stamped on it. Very clear on mine. I guess that's why I got sucked into thinking there was no VIN on the block. The guy on the line only needed to read one to know what engine and trans unit to put in what car....... or at least that is what I was told by a former line worker. Maybe.......maybe not!

Geoff.



How many cylinders are damaged? If it is only a few it might be worth sleeving the damaged cylinders. Just a thought. Chuck
Chuck, I can't answer that yet as the engine has not been dismantled. I'm REALLY hoping that I can get away with a good honing and new pistons. Time will tell. I'm only checking out my options if any.

Thanks,

Geoff.



.

block dates are typically between 10 days and 6 weeks before the actually build date of your car . . for the MCA to say that blocks that are dated 6 months before the build date are acceptable for concours is not only ding a disservice to people that actually have the orig block in their car, it is also laughable . . if your car does not have the orig engine, the date code is irrelevant to any intelligent buyer . . "almost" original is not worth anything close to original.
I agree that numbers matching brings the best value for restored cars. The next best thing is to get a period correct replacement and that usually means a date code prior to the cars assembly date. I have been doing a lot of research on my RR project and found that Plymouth produced the engine blocks up to 6 months before the cars production. Others parts such as intake manifolds, distributors, these usually have date code of up to 6 weeks from production. So I believe that MCA using 6 months is not out of line for being acceptable for concours. The Vin stamp will ultimately identify it as numbers matching no matter what the casting date is as long as it is before the assembly line production date. These of course are just my personal opinions and what I have found while researching my new project.
John, interesting! Thanks. I may just contact the MCA and find out for myself. Now I know for sure that previous info about VIN numbers not being on Cleveland block was bollocks, I am REALLY hoping I can rebuild my original engine for value sake. However, lets face it, these are not million dollar cars and most future buyers may not even care as long as it runs strong and looks good.

Geoff.

 
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Thank you too barnett468, This is the info I needed and yes, I agree, almost is not the same, but close may have to be good enough. As said before, this is all for a back-up plan should MY block be not usable without sleeving it and that is something I really don't want to do......yet.

As for the MCA part, it is amusing how much miss-information there is out there. I was told that by a friend who is restoring a 70 Boss 302 to original spec. Hmmmm!
No prob . . If it is a BOSS or other rare car than it is a little different story, but my point was that its not wort trying to find the right date or pay a big price for one on a more common car because it wont affect the price much because the engine is not special but the car is still a Mustang.

 
Thank you too barnett468, This is the info I needed and yes, I agree, almost is not the same, but close may have to be good enough. As said before, this is all for a back-up plan should MY block be not usable without sleeving it and that is something I really don't want to do......yet.

As for the MCA part, it is amusing how much miss-information there is out there. I was told that by a friend who is restoring a 70 Boss 302 to original spec. Hmmmm!
No prob . . If it is a BOSS or other rare car than it is a little different story, but my point was that its not wort trying to find the right date or pay a big price for one on a more common car because it won't affect the price much because the engine is not special but the car is still a Mustang.
Barnett, I agree completely. To be honest, this discussion has gone way past what I intended, but all comments have been very helpful and I continue to learn and that's a good thing!! IF I have to use another block, it would be the 1A26 if it checks out to be good, but I would never scrap my original block. Actually, I have almost enough parts to build a complete replacement engine, just missing an intake. If I did that, I could keep the entire original engine intact. Just another option!!

As for my friends BOSS, yes it is an original G code.......... love that car!!

Thanks to all,

Geoff.

 
My 72 Mach 1 was built in August 71, the block has the last 6 digits Vin # stamped on the drivers side back of the block under the head. As far as date codes on the engine go 1 cylinder head was cast in May of 71 the other June of 71 and the block was cast on June 28 of 71 with actual engine assembly taking place on August 19,1971.
Ron, thanks. It is now obvious that blocks did have VIN's stamped on them despite what some websites will indicate. I was under the impression that it was not until the middle of 71(Q codes) that VIN's were used on blocks. Goes clearly to show that you can't always believe what you read or hear.

As explained earlier, I may have to replace my block and was needing info on what would be an appropriate date code so I could at least keep it close to correct. It now is obvious that I will have to rebuild the original engine no matter what the cost. As that engine has not yet been stripped, it may not be as bad as I'm thinking. I guess I'll have to wait and see, soon I hope.

Thanks to all, I now have very valuable information, which in turn will help others. I'll be sure to post the outcome in the coming months.

Geoff.
I am glad to help Geoff. I meant ask if you have the aluminum engine ID tag that is usually attached under the Ignition coil bracket bolt. That will give you the engine assembly date information. Ron

 
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