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block casting numbers

J

jmp

Guest
I was looking for the various numbers on my block. I found the casting number at the rear driver's side (3970010), but I haven't been able to find a date or the partial VIN. Now, this may make sense, since the block is not original (prior owner cracked it). So, I guess my question is, does this make sense -- no date and no VIN?

Can you get the VIN stamped on the block? Is that considered some kind of forgery?

Also, apparently some numbers contain a 3 letter suffix (eg. CKY)... other than the parial VIN on the block, is there any other place that this suffix should be found?

Thx.
 

Tom73

Well-known member
Joined
Aug 21, 2001
Messages
1,427
Location
Round Rock, TX
Corvette
73 LS4 Coupe - 04 CE Conv
Joseph,
The number with the VIN and the build date/usage code are stamped on a machined surface on the block in front of the passanger side head. This surface may extend out about 1/2" from the head and be about 2" wide. If the block has been decked the numbers will more then likely be gone. Decking is where the mating surface on the block where the heads bolt is trued up. That will cut the stamped numbers right off.

A lot of people will restamp the block. Just don't try to pass it off as original.

tom...
 
Joined
Jul 23, 2002
Messages
151
Location
Sussex, WI, USA
Corvette
1980 330HP / 1963 L75 Roadster
If you look on rear passenger side of the block you should see a four charactor code cast in. This is the date the foundry cast the block. I have a spare 010 block and the cast date is F298. The first charactor is the month, in my case "F" means June. The second and third charactors are the day the block was cast and the last charactor is the year. My block was cast on June 29, 1978.

There is also something that looks like a clock cast on the block with a series of dots and a pointer. This designates the shift the block was produced on.

Foundries cast in the above information so they can trace and isolate any blocks (or cylinder heads) that later testing determines a metalurgical problem exists.

Having a 010 block is a good thing as they generally have a higher percentage of nickel alloy content which improves their strength.

Eugene
 

80convertible

Well-known member
Joined
Jan 26, 2001
Messages
416
Location
Asheville, NC
Corvette
1973 converted to 1980 custom convertible
According to an old repair manual I have, CKY refers to a 1972 corvette engine with 4speed tranny and 255hp.

Jim
 
I

intex99

Guest
vin numbers

While everyone is on the subject of casting numbers I looked at the 81 I just got and on the front of block found these stamped numbers or what looks like these numbers
1M1205
5VP
This is where the vin numbers are located on my 80 so know I'm in the right spot and don't see any on backside of engine.
I'm sure these aren't the numbers that should be there if it was the original engine but does anybody know what or where this engine came out of??The car shows 57,000 miles but sure its at least 157,000 and they disconnected the speedo so who knows how many miles.
Not that it really matters much but is nice to know what I'm dealing with.In Chiltons Engine Id chart it shows IM as a 427 and I know its not that engine.
Any help would be most appreciated!
Tim
 
Joined
Jul 23, 2002
Messages
151
Location
Sussex, WI, USA
Corvette
1980 330HP / 1963 L75 Roadster
intex99,

Try looking at the back of the block for the cast in foundry information with raised charactors. Unlike the the mechanically stamped in charactors like you found on the VIN Pad the Part Number and the Heat Date are part of the sand mold the iron was poured into. With a flashlight you should be able to see the Block Casting Part Number and the four digit Heat Date I described in my earlier posting. Both should be located where the block slopes behind the cylinder heads. The Part Number and the Heat Date information will help you determine the vintage of the block.

Eugene
 
I

intex99

Guest
thanx impala,
will do that next time I'm under her which will be pretty soon!Do you have any idea of what those numbers up front would stand for??
Tim
 
Joined
Jul 23, 2002
Messages
151
Location
Sussex, WI, USA
Corvette
1980 330HP / 1963 L75 Roadster
Hello Tim,

I had checked on some web sites and nothing jumped out at me. The block Part Number and Cast Date information would help define the search.

While you're looking at the block again it would be worth the effort to take another look at the stamped VIN Charactors to be certain of what they are.

Eugene
 
I

intex99

Guest
casting numbers

Hello Eugene,
Sorry its been awhile but have been working on alot of things on this 81!
I looked for the casting numbers on pass side back of engine and didn't see any unless they are behind the starter or on the tranny end of engine which I couldn't see anyways! The numbers on front where normal vin numbers are stamped are on 2 lines which are as follows
1M1 205
5VP
The only other numbers I see on the engine is a 3 which is just above the oil filter!
That area is easy to see as I have the steering column out as last owner had someone put in an alarm system and they tried to wire into column and only put back 1/2 the parts!
Any other ideas would be helpful and thanks for all the help you've already given me!
Tim
 
R

RalleyRed

Guest
Tim,

Fancy finding you here, lol

I just went and looked at my motor because something about the numbers you listed seemed familiar(sp)

What you've got is a crate motor from GM. I can't tell you which one though.
You should be able to see 2 more sets of numbers, 1 one the drivers side at the back of the motor. Mine is 342 and it's right next to the clock which tells you what time it was cast .

On the passenger side again at the rear of the motor you'll find an 8 digit number. Mine is 10243880.

I'd call a GM dealer that deals with their performance catalog and give them the numbers you find, they should be able to tell you exactly what you've got.

Rick
 
I

intex99

Guest
Howdy Rick,
Hows Chittenango NY these days!Or should I say hows the Yellow Brick Road!!
I just couldn't sleep not finding those numbers so crawled back under her.On the drivers side above oil filter on the tranny edge if found some numbers.They had some writting above them like hech---- but hard to read as couldn't get all gunk out of it.But the numbers read like this 10066033 at least the last 3 looked like a 3 but was kinda blended into the one before it!
Yeah I'm pretty sure its crate but last owner really couldn't tell me squat about it and must have been looking at a different Vette when I asked him all about this one!
Thanks all!
Tim
 
I

intex99

Guest
I will check out a GM shop to find out what I have here and just want to thank everyone for their help! I just can't get much sleep when stuff like that keep rolling around in my head!
 
I

intex99

Guest
Thanks billybob!
That was just the site I was looking for!Found out exactly what I wanted to know and then some!:_rock
 
B

billybob

Guest
intex99,

No problems, as a fellow shark owner,I too was on such a quest and had a bugger of a time locating anything, so with what information I can provide I'm more than happy to give it up.
 

cruzer99

Well-known member
Joined
Aug 27, 2002
Messages
702
Location
Granite Falls, N.C. USA
Corvette
99 Navy Blue Pearl Vert. NCRS Member

Lucy64

Well-known member
Joined
Jul 20, 2002
Messages
369
Location
South Riding, VA, USA
Corvette
1964 Red Convertible and 2005 DSOM Z51 Coupe
Good site

This site is very good. I verified the number on the block number of my 64. This site could very helpful for anyone looking for this info.
 

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