When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
I have looked at a 69 L89 coupe for sale that at first appeared to be numbers matching until I looked at the block which is a 3963512. The car was assembled in October 68 as vin number 194379S705903. From my research, I understand that block was not used in Corvettes until late in the model year, which would indicate it is a replacement block which has been restamped with the original numbers. Can someone more familiar with this situation either confirm or deny this possibility? If it is a restamp, but all the rest of the engine components are correct, how much of a hit in value would it be? Current owner is asking $46,000. Front clip has been replaced and does not fit great. Rear end is from a 1970. BTW, I did not see the block casting date. I know they were produced starting in 68, but I don't think they would be correct for an early production 69. Any thoughts? Also, owner has no documentation.
Last edited by Corkscrew; Nov 25, 2016 at 12:39 PM.
Reason: Add info
I am not familiar with " FD or SD ". Can you please elaborate?
black book list the FD as first design and SD as second design but makes no note for the 512 block used in 69 production. with a 70 rear in the car, a NOM with a forged stamp is not a good way to start the story on proving its a real BB car let alone a real L89
Last edited by Nowhere Man; Nov 25, 2016 at 04:02 PM.
The 3963512 block began to be phased in around October 1968. The car in question was built mid-October 1968. Does not prove anything with regard to originality, but a 512 block in this car was at least possible.
You have given no information on which to base assessment of whether the car is or is not a restamp.
The fact that there is no paper documentation will hurt the value of the car whether it has the original engine or not.
The 3963512 block began to be phased in around October 1968. The car in question was built mid-October 1968. Does not prove anything with regard to originality, but a 512 block in this car was at least possible.
You have given no information on which to base assessment of whether the car is or is not a restamp.
The fact that there is no paper documentation will hurt the value of the car whether it has the original engine or not.
Regards,
Stan Falenski
Ok, Stan, here is another bit of info - the block casting date appears to be I 4 8 or I 4 9, Sep 4 1968 or Sep 4 1969. What do you think? See below.
Let me back up a moment. It is possible to see 3963512 blocks in October of 1968 so it isn't a stretch that some of those blocks might have September 1968 dates. So far so good, but here's the problem...
If this car was built in October of 1968, the block would have to be built and assembled before the build date of the car. Assume for a moment that we are misreading the date code and it is actually an "8" for the year... Works OK, but a couple of problems. First, I don't recall seeing a "4" cast into a block that looked like that. Second, blocks this early usually had the date code cast into the passenger side of the cylinder case, not the bellhousing flange as the later (around January 1969) castings are. I am not sure whether this casting orientation occurred on 512 blocks as it did with the 439 and 270 blocks... I just don't remember (I've made some calls). In any case, if that is a "4," I'd be digging for more information.
If the last digit is a "9" then the casting date is off almost a year after the car was built (plus the issue with the "4"), so the answer there is pretty clear.
Forgive me if I missed it, but did you post a photo of the stamp pad for this engine? I don't recall seeing it. In any case, a photo or two of the pad would certainly be helpful.
Let me back up a moment. It is possible to see 3963512 blocks in October of 1968 so it isn't a stretch that some of those blocks might have September 1968 dates. So far so good, but here's the problem...
If this car was built in October of 1968, the block would have to be built and assembled before the build date of the car. Assume for a moment that we are misreading the date code and it is actually an "8" for the year... Works OK, but a couple of problems. First, I don't recall seeing a "4" cast into a block that looked like that. Second, blocks this early usually had the date code cast into the passenger side of the cylinder case, not the bellhousing flange as the later (around January 1969) castings are. I am not sure whether this casting orientation occurred on 512 blocks as it did with the 439 and 270 blocks... I just don't remember (I've made some calls). In any case, if that is a "4," I'd be digging for more information.
If the last digit is a "9" then the casting date is off almost a year after the car was built (plus the issue with the "4"), so the answer there is pretty clear.
Forgive me if I missed it, but did you post a photo of the stamp pad for this engine? I don't recall seeing it. In any case, a photo or two of the pad would certainly be helpful.
Regards,
Stan
Ok, here is the stamp pad. Still trying to determine if it is a restamp or not. The pad has obviously been abused somehow. Intentional or not is the question. The vin derivative looks identical on the pad and the trans. First characters are deeper and more pronounced than serial numbers in both places.
Hello Stan,
I have a 512 block in my 69 coupe that was built in Feb 69. The block was cast Jan 28, 1969 and the date is cast on the passenger side of the block. So that L89 would have an unusual location for that cast date. However, my engine is a 390hp so I don't know if that makes a difference.
And the 4 does look odd. They are usually closed on top but I don't know all the fonts they might have used.
I have a 512 block for my 427/390 dated J28, I was told it is the earliest this select person I spoke about it to ever saw, talk among yourselves.............................B Block casting date is on side near front of starter,
This block, dated J 2 8 (October 2, 1968) has the date code on the SIDE of the block.
Would not a 512 block dated I 4 8 (Sep 4, 1968) ALSO have the date code on the SIDE of the block.
Doesn't this lean toward this date code being I 4 9?
Here is a date code from a exhaust manifold. I only show it to demonstrate the 'open' 4 style of font. Apparently they did use this type during that time period.
Last edited by ed427vette; Jan 5, 2017 at 11:45 AM.
Here is a date code from a exhaust manifold. I only show it to demonstrate the 'open' 4 style of font. Apparently they did use this type during that time period.
Ed,
Good information. Might be brain fade, but I don't recall style of "4."
Assuming the "4" is correct, it appears to be I 4 9... Located on the bellhousing of a 3963512 block. For September 4, 1969, the 3963512 casting would probably be the only casting number being used for a 427 and puts the block casting date in the location it should be.
Now the problem comes when you get to the pad.
The pad surface is obviously damaged... The dual disc clutch may not have been available... The block casting and assembly dates are after the car was built (by almost a year)... There are some other pad issues that might be in play as well.
If the date actually is I 4 8, then you run into the question of the orientation of the date... Why isn't it on the side of the block?
Throw in the fact that there is no documentation on top of all of that.
If it is a neat old car and the purchase price wasn't/isn't too high, a lot of what we are looking at really isn't critical... Just drive it and enjoy it. If, on the other hand, you're looking at a high dollar car billed to be the "real deal," then you may want to look at other options.
Do you own this car or are you looking at it as a potential purchase?
I too, have a 512 block and the casting date is G 5 9. It is on the passenger side rear of the block. I wonder when it changed from the side to the rear too.
I too, have a 512 block and the casting date is G 5 9. It is on the passenger side rear of the block. I wonder when it changed from the side to the rear too.
I looked at some K x 69 dated blocks that had the date code on the top rear.
Let me back up a moment. It is possible to see 3963512 blocks in October of 1968 so it isn't a stretch that some of those blocks might have September 1968 dates. So far so good, but here's the problem...
If this car was built in October of 1968, the block would have to be built and assembled before the build date of the car. Assume for a moment that we are misreading the date code and it is actually an "8" for the year... Works OK, but a couple of problems. First, I don't recall seeing a "4" cast into a block that looked like that. Second, blocks this early usually had the date code cast into the passenger side of the cylinder case, not the bellhousing flange as the later (around January 1969) castings are. I am not sure whether this casting orientation occurred on 512 blocks as it did with the 439 and 270 blocks... I just don't remember (I've made some calls). In any case, if that is a "4," I'd be digging for more information.
If the last digit is a "9" then the casting date is off almost a year after the car was built (plus the issue with the "4"), so the answer there is pretty clear.
Forgive me if I missed it, but did you post a photo of the stamp pad for this engine? I don't recall seeing it. In any case, a photo or two of the pad would certainly be helpful.
Regards,
Stan
Hi Stan.
My 69 427 L36 has a build date of Oct 24 69. The engine stamp pad is T1020LM so the engine (512 casting) was assembled Oct. 20-69. The block casting date is J 8 9. I had always thought the block casting date was supposed to be on the side of the block but mine is in the exact same spot as the one in Corkscrew's pic and the lettering and placement is identical to his. I had read previously that this wasn't changed to just above the bell housing until around Dec 69 but this is obviously not true. I would say his casting date is Sept 4 1969 on that block and the location of the casting date is probably correct for the date.
Last edited by CanadaGrant; Jan 5, 2017 at 03:43 PM.
I probably should have been more clear about the block casting dates for the 1969 MODEL year.
Early in the 1969 model year (beginning in August, 1968) the block casting number for big blocks was located on the passenger (right) side of the cylinder case. Ed's (jv04) photos show this well. The location was used for all castings used for Corvettes at this time... 439, 270, and 512 castings.
Around January 1969, the 439 and 270 castings were phased out and the 512 block used almost exclusively. In addition, the casting date was moved from the side of the block to the passenger (right) side of the bellhousing flange. Apparently, the old casting date location ran to at least February 28, 1969 on at least one line... Ed's (jv04) photo and Ed's (ed427vette) actual block is proof of that, but a specific day aside, the casting date location changed around January/February 1969.
Those of you with dates later than this in the 1969 calendar year with the casting date on the top right bellhousing flange... It's right where it should be!
Hi Stan.
My 69 427 L36 has a build date of Oct 24 69. The engine stamp pad is T1020LM so the engine was assembled Oct. 20-69. The block casting date is J 8 9. I had always thought the block casting date was supposed to be on the side of the block but mine is in the exact same spot as the one in Corkscrew's pic and the lettering and placement is identical to his.
For your car, everything seems right in line. October 8, 1969 block was cast... October 20, 1969 engine was assembled... October 24, 1969 car was assembled. Pretty quick progression for a big block Corvette, but all within reasonable production practices for that time.
The car that Corkscrew has referenced has a VIN for a 1969 Corvette built in late October 1968... An I 4 9 casting date would mean the block was cast eleven months after the car was built... That's a problem. If we are misreading this and it is an I 4 8 casting date, then the casting date is in a location it probably shouldn't be until three or four months later. On top of that, the engine is coded for an option that supposedly wasn't available for another three of four months as well.
L89 block mismatch
