327 smallblock numbers

[Jeffrey B.]

Would appreciate some feed back on numbers I can't seem to ID. The numbers are found on the passenger side, rear portion of the block on the bell housing flange just behind the cylinders. I can find a reference to all of the other numbers on my block except these. The numbers are large T5 over small OCNY2.
Thank You.
Jeff

[Monte M.]

Re: 327 smallblock numbers

Jeff,
I think a picture would go a long way in resolving this issue.

Typically that is where the casting date is. If is a Flint block/Corvette block the date will look something similar to "A 10 3" or "F 5 6". The "A" being the month cast with "A" being January, "B" being February, and so on. The second number or set of number is the day of the month it was cast. And, the last digit or two being the last or last two letters of the year it was cast.

If it is an Impala block the date will look the same with the exception of the year being two digits. Such as "A 10 63" or "F 5 66"

Best of luck,
Monte

[John H.]

Re: 327 smallblock numbers

If it is an Impala block the date will look the same with the exception of the year being two digits. Such as "A 10 63" or "F 5 66"

Best of luck,
Monte

Monte -

The 2-digit year format is for Tonawanda blocks, and small-block engines for full-size Impala/Caprice were supplied by both Flint V-8 AND Tonawanda - just depended on the assembly plant location.

[David L.]

Re: 327 smallblock numbers

Jeff,

The link below might be of some interest.

Dave

https://www.forums.ncrs.org/showthread.php?93976-Block-castings&highlight=3858174+block+casting+numbers

[Jeffrey B.]

Re: 327 smallblock numbers

I'll try to send a photo. The area I'm referring to is on the block behind the passenger side cylinder head.

[David L.]

Re: 327 smallblock numbers

Was the block cast in Flint or Tonowanda? You have given very little information about the block.

Dave

[Jeffrey B.]

Re: 327 smallblock numbers

I was primarily interested in finding out what the numbers specifically in the photo represent or are they of no significance?

[Harry S.]

Re: 327 smallblock numbers

It's probably for Tonowanda and 5 is a cast series, maybe. Depending on the cast date and other castings on the block it's probably not from a Corvette. I agree with David more information would be helpful.

[Cecil L.]

Re: 327 smallblock numbers

I believe what you are seeing as OCNY2 is actually CONV2. The T5 indicates a Tonawanda block and they could be found in all non-Corvette full siize Chevy v8 applications including trucks.....not just Impala or Caprice.

[Wayne M.]

Re: 327 smallblock numbers

I believe what you are seeing as OCNY2 is actually CONV2. The T5 indicates a Tonawanda block and they could be found in all non-Corvette full siize Chevy v8 applications including trucks.....not just Impala or Caprice.

I knew I'd seen this CONV2 (or CONV1, or CON1, or CON2) on some cast items before.
Here's what's on a differential carrier I have, cast I_11_8 (Sept 11, 1968)
Anybody have an idea of what the "CON" part stands for ? I assume this diff. part was cast in Warren MI.

[Joe L.]

Re: 327 smallblock numbers

I knew I'd seen this CONV2 (or CONV1, or CON1, or CON2) on some cast items before.
Here's what's on a differential carrier I have, cast I_11_8 (Sept 11, 1968)
Anybody have an idea of what the "CON" part stands for ? I assume this diff. part was cast in Warren MI.

Wayne------


No, it was not cast in Warren, MI as I don't think that GM ever had a foundry located there. Most likely, it was cast at one of the nodular iron foundries GM used to have in Saginaw, MI. It's also possible it was cast at Danville, IL or Defiance, OH but I rather doubt those locations.

[Cecil L.]

Re: 327 smallblock numbers

CONV= conveyor

[Monte M.]

Re: 327 smallblock numbers

John,
Yes, I knew this. I was just trying to give him some basic information about the information on that flange. I should have said it was a Tanowanda block as you did, but sometimes I get so used to saying Impala that I forget the word Tonawanda.
Even after I realized what I had written I realized it was not important enough to the information that he was looking for to change it.
Monte

[Jeffrey B.]

Re: 327 smallblock numbers

I appreciate the feed back provided regarding my initial question. I know the block in my car was replaced at some point in the cars life, however I'm curious because the partial vin is stamped on the block pad and I'm not sure why anybody would have bothered considering the condition the car was in when I bought it. My only other thought was if the motor was replaced under warranty, because it has the right heads, intake, carb, and exhaust manifolds, and the block casting date is Sept 24, 1965. The block casting number is 3858180 which would not have been seen on a production 1966 Corvette. I'll just enjoy the car and drive it like I have for the past 8 years. Life's to short to sweat the small stuff. Thanks again.
Jeff

[John H.]

Re: 327 smallblock numbers

CONV= conveyor

Correct - that's the molding line conveyor the part was poured on at the foundry.