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Old Oct 25, 2014 | 04:03 PM
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So I bought a bundle of parts recently and 1 of the items was a 512 block for 1969. Everything looks good except the date code on the back of the block. The month code has been either ground down or just very faint and somewhere down the line another letter was epoxied over it. I'll show pictures a little later. The front stamping is near perfect, meaning the block codes, dates, and vin all look as real as rain, over the broach marks. 100% positive it's authentic. It is a 30 over motor. My concern is...if I chunk that epoxied letter off and the original letter has been ground off, would that devalue the block significantly. Any and all opinions are appreciated.
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Old Oct 25, 2014 | 04:18 PM
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If the stamp pad was authentic there would be no reason to alter a casting date. This is a perfect example of counterfeiting that's ruined a large part of the hobby.
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Old Oct 26, 2014 | 09:32 PM
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If the original date code appears to have been tampered with I'd imagine the block is only useful for general purpose applications, no more than other old block.
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Old Oct 27, 2014 | 04:17 PM
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Before I do anything with this block, I need to make every effort to reunite the car/block. This motor is the 435hp manual code and the vin # is very legible. I've made an effort to google the vin and came up with 3 hits, 1 was a previous sale, approx. 6 years ago. I called the broker, he's currently looking for info, but doesn't sound promising. The second is from a AutoLocator which has no contact info, just an ad, that I don't quite understand. The last is a listing in the corvette registry with the same info that matches the block, claiming the car has a replacement motor. All this lines up, but I still don't know the best way of contacting the current owner or posting the info. for the owner to track me. Again, need help.
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Old Oct 27, 2014 | 05:38 PM
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Maybe you're overlooking the obvious. The car lost it's original motor at some point. The owner found this block but the casting date was too early or too late so he ground it off and made a new one with epoxy, then stamped the pad to suit. Unfortunately, this practice is not rare.

This motor was then removed for whatever reason and replaced with a third engine.
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Old Oct 27, 2014 | 05:57 PM
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Originally Posted by Mike Ward
Maybe you're overlooking the obvious. The car lost it's original motor at some point. The owner found this block but the casting date was too early or too late so he ground it off and made a new one with epoxy, then stamped the pad to suit. Unfortunately, this practice is not rare.

This motor was then removed for whatever reason and replaced with a third engine.
I can appreciate that possibility, but let's just assume this deck stamp is authentic for now. I'm looking for avenues to reunite the motor/car at this time regardless of the actual chain of events.


FWIW, I do feel confident on my ability to authenticate a pad stamp, not to say the most sophisticated forgery can fool most of us. I've also had at least 2 fairly knowledgeable folks other than my own set their eyes on it. I do have a strong opinion on why the block casting date was altered.
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Old Oct 27, 2014 | 07:09 PM
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Originally Posted by nutt
FWIW, I do feel confident on my ability to authenticate a pad stamp, not to say the most sophisticated forgery can fool most of us. I've also had at least 2 fairly knowledgeable folks other than my own set their eyes on it. I do have a strong opinion on why the block casting date was altered.
I'd like to hear your theory and maybe see pic of the pad.
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Old Oct 27, 2014 | 07:27 PM
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Originally Posted by Mike Ward
I'd like to hear your theory and maybe see pic of the pad.
Not trying to be an *** but I didn't post this to entertain, I'm just trying to put this in the hands of the owner rather than put it in commission in my vette.
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Old Oct 28, 2014 | 03:50 PM
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I hope you are successful in determining that this is indeed the original engine and reuniting it with the car.

Maybe post the VIN here, somebody might know the car?
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Old Nov 1, 2014 | 12:00 AM
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The 3963512 block 1st started production in October 1968 as a 427, and continued through 1971 as a 454. What's interesting about your block is the location of the date code, which was moved from the low side(starter) to the upper rear November 17,1969. Since you know it is a 1969 code, and a rear date, it would have to be in a late November-to-mid-December build Corvette. As to why the date was changed by epoxy, ..... ????? The date tag is affixed by 2 screws, so any alteration would be very noticeable. I'm wondering if this could possibly be a Mcode block, as this is about the time of the 427-to-454 transition, and M does not decode to a particular month. It would be interesting to see pictures of the date stamp, and the front pad .... any chance of that happening?? As Mike has already mentioned, there is no reason to alter the date stamp.

Last edited by Lindstrom; Nov 1, 2014 at 12:05 AM.
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Old Nov 2, 2014 | 12:03 PM
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Interesting to read. I'll go out and have another look at the block that came out of my 1970 BB. It's not the original engine.
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Old Nov 2, 2014 | 12:44 PM
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Originally Posted by Lindstrom
The 3963512 block 1st started production in October 1968 as a 427, and continued through 1971 as a 454. What's interesting about your block is the location of the date code, which was moved from the low side(starter) to the upper rear November 17,1969. Since you know it is a 1969 code, and a rear date, it would have to be in a late November-to-mid-December build Corvette. As to why the date was changed by epoxy, ..... ????? The date tag is affixed by 2 screws, so any alteration would be very noticeable. I'm wondering if this could possibly be a Mcode block, as this is about the time of the 427-to-454 transition, and M does not decode to a particular month. It would be interesting to see pictures of the date stamp, and the front pad .... any chance of that happening?? As Mike has already mentioned, there is no reason to alter the date stamp.
This block has the date down low, not @ the bellhousing flange. I apologize for misinformation in my first post. This block has a T0918LP pad stamp.
At this point, I've contacted the C3 registry, Christian and I have spoken and he is putting a notation for the owner. He has non-current owner info, just as I do. I had contact info who purchased the car from the registry's owner. That sale was 6 years ago. I emailed that owner, no response as of 1 week ago.
I'm at a loss, but the block is tucked away nicely and I don't have any immediate plans for it.
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Old Nov 2, 2014 | 01:04 PM
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'LP' designates an aluminum head L89 engine. Pretty rare.
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Old Nov 2, 2014 | 01:08 PM
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Originally Posted by Mike Ward
'LP' designates an aluminum head L89 engine. Pretty rare.
I'll say, 390 made. That's why I'm focused on finding the car. I still haven't heard any suggestions on how to do this.
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Old Nov 2, 2014 | 02:27 PM
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T0918LP decodes to Tonawanda, September 18, 1969, LP(L89 as mentioned) which means the car would fall in the 33,000 serial number range. First thing to try is put the full VIN on google and see if you get lucky. You can also try the National Insurance Crime Bureau(NICB) to find out if the VIN is in their database reported as stolen, but the NICB is not known for warm, fuzzy email replies(unless you get lucky). I'd still be interested to see a picture of what is going on with the epoxy letter on the date stamp, which makes absolutely no sense at all. It all sounds so ominous. In all probability, according to the build date you gave, the casting date should probably be September(I).
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Old Nov 2, 2014 | 03:24 PM
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Thanx.
I have googled the vin and that's where I landed the "for sale" ads and also the registry information.
My theory on the date alteration...these parts were purchased with a slew of '69 bbc solid lifter pieces, pulleys, tin, carb, etc and the block was naked awaiting machine work. I believe the seller was attempting a fake COPO motor and things fell apart for 1 reason or another. That LP stamping was soon to be wiped clean. It's the only thing that makes any sense to me.
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Old Nov 2, 2014 | 09:58 PM
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Originally Posted by Lindstrom
T0918LP decodes to Tonawanda, September 18, 1969, LP(L89 as mentioned) which means the car would fall in the 33,000 serial number range. First thing to try is put the full VIN on google and see if you get lucky. You can also try the National Insurance Crime Bureau(NICB) to find out if the VIN is in their database reported as stolen, but the NICB is not known for warm, fuzzy email replies(unless you get lucky). I'd still be interested to see a picture of what is going on with the epoxy letter on the date stamp, which makes absolutely no sense at all. It all sounds so ominous. In all probability, according to the build date you gave, the casting date should probably be September(I).
the date of 0918 (sep, 18), could of have been built in 68 or 69, depending on the casting date
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Old Nov 2, 2014 | 10:05 PM
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Originally Posted by LT-1 kid
the date of 0918 (sep, 18), could of have been built in 68 or 69, depending on the casting date
It's a 512 casting, so it's a '69 build.
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Old Nov 2, 2014 | 10:16 PM
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Originally Posted by LT-1 kid
the date of 0918 (sep, 18), could of have been built in 68 or 69, depending on the casting date
Yes, 1969 does have challenges, but since the 512 block was 1st cast in October 1968, the 0918 as a 427 can only apply to September 1969.
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Old Nov 4, 2014 | 09:07 AM
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you gentelmen are right, I forgot the 512 is not all of the 69 427 blocks
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