[greg5436]

a friend of mine just picked this block up over the weekend.he is a LS6 guy and i am a 69 guy.we have never seen a stamping like this..

cast date J-14-69

pad stamp TO2114CO

also has studs on main caps for windage tray.lets hear some opinions on this.thanks greg

 

[136679ss]

my guess is the stamp should be cko and the 21 should be 12/14 not 21 for a really late L78. Yet another hung over foundry worker on the job. lol

 

[oldtimebaseballfan]

Casting dates are hard to change, so maybe it's been restamped.

 

[Dave Birdwell]

my guess is the stamp should be cko and the 21 should be 12/14 not 21 for a really late L78. Yet another hung over foundry worker on the job. lol

A 512 block would be a 454, not an L78 396.
Any pictures? What is the partial VIN stamp #'s??

 

[136679ss]

A 512 block would be a 454, not an L78 396.
Any pictures? What is the partial VIN stamp #'s??

Uh Dave, it could also be a 427, and the closest I come up with is LO for 427/430hp. So much for trying to have a sense of humor here.

 

[von]

J-14-69 would be Oct 14, 1969, which would normally put it in the '70 model year. BUT Camaros definately and I'm thinking maybe Corvettes???? had an extended '69 model year, into Jan, 1970 I believe.

 

[Diamond Judge1]

J-14-69 would be Oct 14, 1969, which would normally put it in the '70 model year. BUT Camaros definately and I'm thinking maybe Corvettes???? had an extended '69 model year, into Jan, 1970 I believe.

Corvettes had an extended model year but I do not think they ran into Jan. Were done sometime in late 69, not sure of the exact time. Only problem is, there is no Corvette suffix even close to CO. Greg, there are too many digits in your production code for the date. Should be four digits, not five as you post. If that is what they stamped, a mistake was made, and most likely you will never figure it out. (Would not be the first!!!). As other posters mentioned, we would need to see a photo of it to help you more, and if the block has a VIN Stamping, we may be able to narrow it down to what type of car it was in, as different car lines were built at different plants. Also, big blocks were sold to other vendors, like boat manufacturers. What is to say that this is not one of them? Also, sometimes blocks had flaws and hung around a long time, so just because a block is cast in a particular period, does not mean it went in a car from the same period. There are rare instances of a block being a year old or more before it was used, due to a repair in it somewhere. Anyway, if you give us more info, we may be able to help you figure it out.
Jeff Dotterer
Dated Components
Diamond Restored Judge

 

[greg5436]

jeff you might be on to something.this block was bought from a boat racer.he said he had it a long time.i will double check that stamp but i think it is correct. no VIN# anywhere on the block. thanks greg

 

[elcamino]

I have a list of Marine suffix codes but the 4CO is not to be found. But my list does not go back to the 70's. I don't know where you would find that info if it exists. My list supposedly came from Chevrolet archives but who knows how complete.

Note-Dead give away of a Marine/Industrial/Irrigations engine are;

numberletterletter (4XA)

fyi
some of the other applications mentioned are;
Marine

• Jet Drive
• Inboard/Outboard
• Inboard
• OR ???

Industrial
Irrigation

 

[TriplblackL78]

i came across this thread by accident but found it interesting in the fact that i have had several 512 blocks and i wonder if this engine was perhaps a crate LS-7 or a LS-7 created from chevy service parts, can you describe any of the specifics on the internals of the engine... crank, connecting rods, pistons
there are a few engine suffix codes out there that i have never seen listed.
i also believe there is a obvious distinction between a 427 "512" and a 454 "512"

john

 

[elcamino]

fyi

per a older GM performance parts catalog, the LS7 crate engine carry th2 suffix XCH and the LS6 crate XAA.

The book does not mention what the block casting number is/was. Its gives most of the other parts but not blocks.

 

[greg5436]

it was only a block,but the block was notched for 454.thanks for the info everybody.after seeing the info about marine blocks it looks like it could be something like that. thanks greg

 

[TriplblackL78]

just out of curiosity does it have high distributor casting/support or low?

 

[David Bates]

it was only a block,but the block was notched for 454.thanks for the info everybody.after seeing the info about marine blocks it looks like it could be something like that. thanks greg

I have two early 427 '512 blocks and they are both notched. No distinction between the 427 and 454 blocks.

 

[TriplblackL78]

the distinction between the two "engines" could be in the casting area below the intake for the ditributor, if someone has had a 4 inch stroke (454) crank come in the early style block it would be news to me...
that in turn would be a difference between a 427 512 and a 454 512 as production would go of course the parts are interchanging

john

 

[Chris R]

The only thing I can add is that with a late 69 date (october). 427 production would have likely stopped and 454 began by then. Unless of course the crate and over the counter engines.

 

[supersport6667]

I have a 67 #351 4bolt block and the deck stamping starts with T then has a 5 digit date code ending in 7 (I was told for model year) and then a 2 letter code I cant find anywhere. I dont have the block here at the moment or I would post actual deck stamping. I was told the block is most likely out of a 1967 boat because they used a 5 digit assembly date ending with the model year. Strange thing is block was cast August 1966 and assembled shortly thereafter, I dont know if boat model year changes in august/sept. of previous year like cars do.