954rider

I have a 63 convertible with a L-76 340 hp engine. The block number is 3782870, and the vin stamp (T0506RE) matches the vin #. Where the date code is usually located on the right rear of the engine, there is the word conv1 cast into the block. Is the correct for a convertible? I have never seen this before and was looking for some info on what it means. Anybody have any ideas ?

Mike Ward

Not sure how T0506RE could match your VIN as this is the engine assembly code. It also could mean that this not the original engine for your Corvette.

Are you sure it's a 'T' and not an 'F'? Got a pic?

The symbol conv1 means the block was cast on conveyor 1, nothing to do with convertibles.

Boyan

If it has a T assembly stamping instead of an F, its not a Corvette block. Either way, the casting date should be in the same location.
Boyan

Chuck Gongloff

Here's a date code embossment.

Located on the top of the bellhousing flange... to the passenger's side of the distributor.

As others have said, your engine stamp should begin with "F" for Flint/Saginaw. "T" indicates Tonawanda, NY where no 63 Corvette blocks were cast.

Chuck

954rider

It's definitely a T. By matching, I meant the vin # on the block before the T0506RE, matches the body and frame vin #s. Don't have a picture ready yet, but I compared it to a 63 coupe sitting right next to it and it looks identical to that one. I am 99.9 % sure it is a matching numbers block, I have just never seen the conv1 cast into a block before.

JohnZ

Then it's definitely NOT a Corvette block, and certainly isn't "numbers-matching" - no Tonawanda-cast or -assembled 870 block was EVER used in a Corvette. What is the casting date code?

954rider

The date code is what I am trying to figure out. There is no date cast into the block at that location, just conv1. There is a time dial stamped into the top of the block on the casting number side, but that only has an arrow and some dots. I'll try and take some clear pictures and post them later, maybe someone can decipher exactly what I have.

bluestreak63

What is the body build date on the trim tag? And you say the VIN number on the tag next to the trim tag under the glovebox matches the VIN on the engine pad?

Also, you said you compared it to a 63 coupe next to it....are you saying the engine date/code on the 63 coupe also begins with a T?

ctjackster

Lots of knowledgeable guys on your thread already. I am curious about the engine stamp pad, which you say bears the production number portion of the VIN as well as a T (for Tonowanda) engine assembly code. Would love to see a picture of such a pad. And yes, the block casting date would help too if you find it.

Mike Ward

Try looking here:

vettebuyer6369

Id love to know what you are talking about, re: "it looks identical to a 63 coupe." Whats identical? The pad? The assy code?

By the way you are insisting the numbers match, Im sure you are convinced of this and do not want to hear anything else, but one thing is true: it IS possible that the VIN derivative on your pad does in fact match your car's VIN, AND you have an assembly date that starts with a T.

However, that would mean that the VIN was ground off the block and your car was re-stamped by a stamper that wasnt smart enough to know a Corvette block assy date has to start with an F.

It might match, but it would be a terrible fake.

954rider

Let me see if I can clarify. By looks the same, the coupe block pad style and type of letters and numbers looks the same as the convertible stamp pad style letters and numbers.The coupe starts with the letter F.
I'm not saying by any means that this a 100% matching numbers car, which isn't really a concern of mine. I was just trying to research all the numbers on the car and ran across the conv1 cast into the block where the date code should be and have never seen it before.
I will look again in the additional recommended spot for a date code and post some pictures later today.
The date on the trim tag inside is G3. All the numbers I look up show the car as a 63 convertible with a mid March build date. It has a CB rear diff (3.36 posi), borg warner tarns, 2 1/2 inch exhaust, tool wells under the seats.Correct 340hp intake.Vin #1107XX
I'm not trying to insist it's a numbers matching car, just wanted to know the history of the car and what the conv1 meant in place of a date code.

Chuck Gongloff

IIRC, the time dial stamps on 870 blocks began in 1964. I"ve never seen a 63 block with the casting clock.

It's been awhile since I read up on the casting clocks, but IIRC, the head of the screw in the dial, phillips vs. slot, indicates the shift, and the dots around the perimeter indicate hours within that shift.

That way, if there was a problem with engine blocks, they could trace it down to the shift and hour when they were cast.

That being said, there should still be a casting date on the block.

Tonawanda small blocks typically have a "two digit" year in the date.

For example:
A 12 63 would be Jan. 12, 1963. for Tonawanda, New York.

A 12 3 would be Jan. 12, 1963 for Flint/Saginaw, Michigan.

Chuck

emccomas

Mike Ward has the right idea. I have seen many Tonawanda blocks for 1963 and 1964 that had the date code in the location that Mike indicated.

I have also seen a number of restamps using a Tonawanda block.

My guess is that this block started out as a T0506R, and someone added the E afterwards.

Post a picture of the engine pad.

Chuck Gongloff

Here's a link to a discussion of casting clocks.

http://www.chevytalk.org/fusionbb/sh...hp?tid/289108/

Post a picture of the pad showing the VIN derivitive of the car and the assembly date and suffix.

Chuck

Mike Ward

The engine assembly date is May 6th. Either it was built two months after the car was assembled or ten months earlier.

5thvet

You have to feel bad for the guy. He comes on to see what conv1 means and finds out he engine is not from a Corvette......

954rider

Ok, here are some pictures. So before I feel like I woke up at the dentist's office with my pants around my ankles, all I am interested in is what the conv1 is. Or maybe even what this engine really is or what it came from. So the engine didn't come out of a corvette, I bet it's not the first car without the original engine in it. Maybe i'll put a big block in it just because I can.
Thank you for the replies and information.

Mike Ward

CONV1 was explained in my first post. Very common.

Casting date is D2963, April 29 1963 and also confirms via the two digit year codes that it's a Tonawanda block. How about the pictures of pad?

Boyan

OK, so we narrowed it down finally. Tonawanda block with 63 date. Confirms what the assembly stamping indicated.

Boyan